# Poor Mans Auto-Dosing



## magicmagni (Nov 7, 2003)

**** Final Design on page 2****

I'm wondering if no one else has thought of this before?

I found a way to automatically dose my micros using an air pump and a bubble counter. I had all the items on hand already so it really didn't cost anything; however one can probably set forth and rig this up for around $40+-? 

Let me explain:

Air pressure from a standard aquarium pump is used to pressurize a fert solution into a backwards confiigured bubble counter. This pressure forces the solution into the tank. The "drip" rate is controlled to a point with the air pressure from the pump- this is sort of like a "coarse" adjustment. The "fine" adjustment is done with a standard valve on the fluid side of the line. One can fill the bubble counter with the total amount of traces they want to dose for the week then add distilled water to fill the bottle to where the neck starts. I generally find a drip rate of 1 drip every 30-60 seconds will empty the contents of the bottle into the tank within a week, but I recommend one experiments with plain water first to get an idea of how it works.

I've been running this system now for about 3 weeks and must say I am quite pleased although one of the tougher things for me is getting the drip rate just right with the standard air valve on the fluild side. This has made for quite a bit of tinkering to get just right, but overall I think it's a feasible alternative to some of the other methods out there.

Let me know what you all think. Any questions?


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## turtlehead (May 31, 2005)

any pictures of this? I'm interested.


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## briandmiles (Feb 23, 2005)

Yeah, the devil is in the details so post everything you can think of. All the parts you used. Where were they originally purchased and how are they all hooked up? Do you use a timer? Can you supply a drawing or diagram? If this idea can be refined to the point that it is reasonably predictable I can see a lot of people using it. 

Brian


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## m.lemay (Jul 28, 2002)

I like the whole idea a lot. 

The only difficulty I see is getting it to be reliable and accurate to a degree. Post up some pics, so we can all get an idea of exactly what you got going on, and maybe we can refine this thing online.

Marcel


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## m.lemay (Jul 28, 2002)

Heres a quick sketch of what I think this contraption might look like.


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## BlueRam (Sep 21, 2004)

Could this be done with gravity feed too?


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## bharada (Mar 5, 2004)

BlueRam said:


> Could this be done with gravity feed too?


Kent has their AquaDoser which is gravity fed using an IV-like drip tube. I'm seriously looking into getting a few of these as I'll be going on a three week vacation in August and anything that'll eliminate my brother-in-law having to touch my tanks is good.

Based on last summer's evaporation rates I figure if I empty two 5g Kent dosing containers into my 125g tank over three weeks I'll be able to dose and top off the tank in one step. Same with using two 2.5g jugs into my 40g tank over three weeks. Using two jugs over each tank also allows me to have macros in one and micros in the other.

My trouble tank is my 20g, which isn't open top (so little evaporation) and doses using PPS, so minimal daily input (1ml PPS, 1ml Excel, and 1ml TE per day). Because I don't have masssive evaporation in this tank I can't dilute the doses and dump a bunch of water into the tank. I'll need to spend a bit more time thinking about how to handle this tank.


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## shalu (Jan 16, 2003)

I have the Kent unit. Used it once and done with it. Hard to keep the rate steady. Bought this dosing pump. Will set it up soon, probably will use the Kent container to feed the pump.


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## bharada (Mar 5, 2004)

shalu said:


> I have the Kent unit. Used it once and done with it. Hard to keep the rate steady.


What size container did you buy? Maybe I can borrow it from you to try out? I'm not looking for precision dosing, but a semi-steady drip to last out the three weeks I'll be gone. It would be interesting to just let it run for a week to see the amount it drips.


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## shalu (Jan 16, 2003)

it was like 2 gallons. Sure, you are welcome to try it, but the drip counter is now flooded with water. The main problem is that the adjustment knob is really hard to control, any small change there, you get huge rate change, from no flow to way too much flow.


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## magicmagni (Nov 7, 2003)

OK, OK.... a picture says a thousand words anyways so here are some pics of the setup. BTW you got it pretty much Marcel.

Here's a pic of the air pump and bottle. I'm using the green lines. The clear ones are for something else. FYI the air adjustment valve is built into the pump.









Here's a close-up of the cap. See how I put the plastic connectors through the cap. I drilled them out slightly undersized to secure a tight fit. I didn't even have to use any sealant, but it wouldn't be a bad idea. Notice that only one line (the one that carries the fluid to the tank) goes to the bottom of the container into the fluid.









Heres a pic of the drip adjuster tank side. Note that it is a simple off the shelf valve from the LFS. Side note: Perhaps a high precision needle valve like the ones we use with C02 would work better? Or perhaps it may clog? I may have to try and see.









Dripping into the tank. Notice that the line is elevated above the water line. This does two things. It allows you to count the drops into the tank and it eliminates the possibility of water siphoning out of the tank in the event the pump goes off.









That's it for now. Fire away if anyone has any questions.

Jeff


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## jhoetzl (Feb 7, 2005)

While I Like the idea, using a glass bottle concerns me a bit...if something causes the output to clog, you might get a nasty "incident" with that bottle, filling it with air...then again, depending on the pump, the tightness of those seals, the pump might blow first...


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## bharada (Mar 5, 2004)

Sha,
Are you using the dosing pump only for micros? It would seem that you'd need another one for macros so that you don't get the Fe in the traces precipitating out of solution.

That means I'd need six pumps to cover my three tanks...$360 for the pumps alone. Ouch! But no one ever said keeping high-tech tanks would be cheap.


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## magicmagni (Nov 7, 2003)

jhoetzl said:


> While I Like the idea, using a glass bottle concerns me a bit...if something causes the output to clog, you might get a nasty "incident" with that bottle, filling it with air...then again, depending on the pump, the tightness of those seals, the pump might blow first...



A plastic soda bottle could be used inplace of the glass bottle, but I really doubt that the pressure would be high enough to cause a problem.


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## magicmagni (Nov 7, 2003)

bharada said:


> That means I'd need six pumps to cover my three tanks...$360 for the pumps alone. Ouch! But no one ever said keeping high-tech tanks would be cheap.


What's nice about the "airdoser" Idea method I'm thinking is that for the price of a "T" and some extra tubing and a bottle you can run macros too. I'm actually thinking of running another bottle for my macros, hopefully the pressure drop isn't too much...we'll see.


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## shalu (Jan 16, 2003)

Bill, I got the dosing pump but have not set it up yet. I intend to use it for macros, mix NPK. I use two Eheim liquidosers(got one of them really cheap from Ebay) for trace/micros right now.

The air pump idea is really interesting, I might try it on one of my tanks. The only problem is, none of the air pumps I used so far is really quiet.


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## bharada (Mar 5, 2004)

I'm getting some side cash for a freelance jog I did a whlle ago so I just went ahead and ordered the six pumps and some tubing. If it were strictly for day-to-day dosing I might be more inclined to try a less expensice alternative. But with the long vacation looming at the end of summer, I'd rather spend the money and get the added control offered by the pumps.

The Eheim liqiudoser would be nice, but the pumps will allow me to auto top off, too. I'm figuring that the 40 will lose about six gallons of water due to evaporation. The 125 will be more like 12 gallons lost. During my vacation I can mix my macros up in one 5 gallon bucket (suitably diluted) and micros in another.

My 20 will be the only one that the luiqidoser would've worked on since it's close topped with minimal evaporation, but this way I'll have a consistent setup throughout the house.


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## g8wayg8r (Dec 24, 2003)

Finally, I have a use for that old air pump in the basement. 

I love this method and would use it over the gravity feed any day. That method depends on the head from the height of the solution in the container and it will vary greatly unless you have a reservoir like some of the ultrasonic humidifiers that keep a constant water level. That's way more complicated that the air pump method. Since the head for the air pump method is determined mostly by the run length of the tube from the bottle below the tank to the rim of the tank, the amount of ferts or water in the bottle is almost irrelevant. The dose rate should be relatively constant.

Simple, inexpensive and effective. Gotta do it.


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## scolley (Apr 4, 2004)

*Go for it!*

Just wanted to jump in... been watching quietly. If you can make this clever solution work magicmagni, you'll have done the community a great service!

I'm looking forward to seeing how this works out long term! roud:


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## magicmagni (Nov 7, 2003)

Thanks for jumping in Scolley. Well I've taken so much from this site that I didn't even think twice to contribute this post when I thought this up. I mean heck if everyone didn't share their ideas we wouldn't have all of these plant specific gadgets we all use to make our lives easier. -DIY reactors and Yeast CO2 to name a few.

This is a feasible alternative to whatever else if out there. Just note that this method is to daily fert dosing as DIY CO2 is to injecting C02. It is in the ballpark, but not exact. I think I need to make that clear. Also note that the small air pump laying around from your 10 gal isn't going to cut it on that 100 gallon. What I use is a Tetra tec pump that was rated for 100 gallon tanks if I remember correctly. I can look up the exact model if anyone is interested, but it's the one with the green dials on the sides and two outputs

Update: I was cleaning the Garage- well actually looking for something else and I found a clippord needle valve from one of my Co2 rigs of several years ago. One end is barbed and the other is threaded. I went ahead and swapped out the cheap plastic air valve for this and I like it much better. It's easier now to adjust. The barbed end is connected to the supply and the threaded side has a short piece of airline that that I was able to slide over threads. This side directs the drops into the tank a little better. Note that the hose is still suspended above the water so that I can see the drop rate.

The only downside I note with this system is that when starting a new fert solution you have to open the valve all the way up so that you can "prime the line." Then when all the air is out and you have a good flow you can taper down the flow with the valve to get the drip rate you want. So there is a bit of tinkering, but its an extra 5 minutes and then I'm set for the whole week although I must admit I'm spying on the drip rate whenever I feed the fish just to make sure. While it's not perfect I can usually set it so that the container empties into the tank in about 6 days give or take 4-6 hours. One can also experiment with the starting solution size to further fine tune it. More solution=longer time to finish, Smaller solution= less time to finish. I must note again for anyone trying this to use plain water to experiment until you get the hang of it.


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## magicmagni (Nov 7, 2003)

Heres another update. I was having some problems with the hose extension that I had comming off the needle vavle. It seemed to be throwing off the drip rate so I removed it and modified a bit.

Here's a pic of how it is now. I used a paper clip as a sort of holder for the vavle and attached it to the filter pipes. It is alligned with the cutout in the hood of the tank.


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## magicmagni (Nov 7, 2003)

Here's another update on the airdoser. I actually got it working pretty good, but it took some time. I actually stopped using the needle valve as it was getting clogged too easily. I went back to original standard plastic valve. Another thing that I did too was swap out the original Sobe bottle for a 2L bottle. I did this because I wanted a faster drip rate. It seems that a drip rate of 1 every 3 to 10 seconds works better and is more consistent rate for the plastic valve. roud:


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## scolley (Apr 4, 2004)

These honest, long term use reports are what makes this a good thread IMO. It's one thing to say "I built it" and it's another, far more valuable thing to say "I built it, have improved it, and am still using it." roud: 

If you are having trouble with the flow, have you looked at other method to control the flow? Aquatic Eco-Systems  seems to have a good selection of valves.


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## magicmagni (Nov 7, 2003)

Thanks!! I forgot about that website. A lot of possibilities. Feel like a kid in a candy store!! Although another idea crossed my mind: get rid of the valve all together!!! Am I losing my mind? Maybe, but I'm starting to see deficiencies in my plants even though I am adding the same amount of ferts weekly that I was adding before. The only change I can think of is that before the plants were getting a dose all at once ie. I dumped several capfulls of Flourish and Flourish Iron at a time a few times a week- giving surges of nutrients. Whereas with the doser it's getting a small amount at a time. For some reason it seems to me my plants prefer the former.

I wonder what others who are using other dosing systems would say to that? Perhaps this is not an issue with their setups because it does not constantly administer the dose, but rather shoot a day or two worth of ferts in the tank when the timer goes off? I'm thinking I may want to adapt that method of administering the dose with the airdoser. So instead of using a valve just put the airpump on a timer to go off for X amount of time every few days. I think they have programmable ones that can do that?


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## scolley (Apr 4, 2004)

You can get a programmable timer ($20-$40) to do that. But I really have a hard time accepting the proposition that it matters. In fact, I have a hard time believing there is any difference between dosing every other day, and dosing daily.

Think about it. Let's say you target Nitrates to 14ppm. On a given day you dose so that it is right on 14ppm. Then two days later, it's fallen to 11 ppm, and you dose it right back to 14ppm. I cannot buy the concept that the swing back and forth between 14 and 11 matters to your plants. Both are enough, and not that far apart.

IMO you are barking up the wrong tree. If you see improvements when you dose manually, I think you have problems with your auto dosing amounts. Only rigorous testing and record keeping will answer this question for you.


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## magicmagni (Nov 7, 2003)

You know I think you got a point there. I went back through my logs and sure enough I was dosing more traces when I was dosing manually before using the doser. For some reason I stepped it back, probably just need to up the dosage back to what it was before.


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## scolley (Apr 4, 2004)

Yeah, I think that an unexpected drawback to autodosing, no matter how you accomplish it, is that you have to have records. You've got to know how much of what you are putting in your dosing reservoir, and at what intervals. Since you can't be certain of how much is going in (at least for DIY rigs), so your records are the only way to know how much is being used.

And then, on top of that, you've got to do periodic testing still. Otherwise you don't know when to change your mix, or your amounts.

Auto dosing is automated, but unfortunately not magic. It still takes work. But if you are doing it right, you should eventually be doing a lot less work, a lot less often. roud:


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## magicmagni (Nov 7, 2003)

Well here's another update on the system. I am still using it for micro dosing (haven't had time to mess with setting up another bottle for macros yet). I settled on what I call "the final design" because it has been in operation the longest amount of time without me fiddling with it. Here is a crude drawing of it as it is now.










Since the last time I checked in I've made a few mods:

1. Revised dosing control: I have decided to use a $15 digital timer to turn the pump on and off to control the amount dosed to the tank. Instead of restricting constant flow of fluid with valves I'm now letting the flow go unrestricted and just controlling the amount of time it goes into the tank (like you would do using a traditional dosing pump). This takes care of noise issues (don’t have to listen to the pump all day long), wear and tear issues of the air pump being on 24/7, and eliminates high pressure build up that was present on the old design. I'm currently setting the air pump to run for 2 minutes.

2. Larger reserve: The system now uses a 4L wine jug. This is the type with the screw on top. (Actually they are identical to the sobe bottle tops.) The main reason for this was because the unrestricted output (remember I removed the needle valve) more liquid could pass in a given amount of time. The shortest time interval the digital timer could do was 1 minute intervals. Probably 40 sec interval would be perfect, but I had to improvise so diluting the fertilizer in more water was the solution. Not a bad thing (think of it as a auto top off too)

3. Solution mixing: Sometimes when the trace solution sits things settle to the bottom so I decided to add an air-stone to the solution bottle. Before air just ran into the bottle above the solution level just under the cap, but now I've run a airline to the bottom with the air-stone so when the air pump goes on it agitates and mixes the solution up a bit. A concern with this is oxidation, but it is only for 2 minutes a day- I doubt that it is enough to really do anything, but mix the mixture up a bit. One thing to note is that a check valve should be used on this airline or else the mixture could siphon through the air-stone and to the pump.

This system has been in operation for the last 4 months without a single problem. Works extremely well at this point. Pretty much just refill the bottle after my water changes on Saturday and it's empty by Friday afternoon.


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## magicmagni (Nov 7, 2003)

To recap on what is going on here. I am using air pressure generated by a standard aquarium air pump to push liquid from a bottle into the tank. The amount of fertilizer to the tank is controlled by limiting the amount of time the pump is on. This is done with a programmable digital timer that is capable of running for as little as a minute per day. The amount of liquid administered to the tank is a function of 1. how much fluid is in the fert container and 2. how long the pump runs 3. (but to a lesser degree) how much pressure the pump produces. Manipulating these three factors will yeild the desired results: dosing the proper amount of fert liquid solution per day. Some trial and error is reqiured, but not anything that can't be sorted out in an afternoon or two.


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## Betowess (Dec 9, 2004)

That is a really interesting alternative to the peristaltic pumps. Do you know the ~ cost of that air pump? Great thread.


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## magicmagni (Nov 7, 2003)

Well the cost on the pump is really going to depend on how far you need to push the ferts. In my case I needed to push the ferts about 4' so I used a more powerful pump that I had sitting around. I think though that it was around $30 at my LFS. It was a tetra tec AP200 http://www.mops.ca/cgi-bin/SoftCart.exe/skus/ap/APTE-26095.asp?E+scstore The tetra tec deep water ones may work well too. I like it because it has two outputs (one for macros one for micros) and they are both independently controlled with knobs on each side. Compare that to closer to $100 for a traditional dosing pump and you see savings. Most people may even have pumps laying around in which case it may only cost you a few bucks for the timer and some air hose.


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## jgc (Jul 6, 2005)

I just had a fun thought. It started with deer feeders - they are basically irrigation timers that trigger relay timer (the relay stays open for x seconds after the initial power is applied. It resets after power is turned off - just saw that these can be pretty cheep on ebay)

Then I continued the thought - with relays I could even make that timer run my lights. I am not sure if I will have time to pursue this thought - but think it may be the beginging of a poor man's aquarium controler. Especially since I have a irrigation timer sitting in the garage unused at the moment...


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## Wasserpest (Jun 12, 2003)

jgc said:


> Then I continued the thought - with relays I could even make that timer run my lights. I am not sure if I will have time to pursue this thought - but think it may be the beginging of a poor man's aquarium controler.


Please do continue... :thumbsup:


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## magicmagni (Nov 7, 2003)

Cool:thumbsup:


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## aanderson09 (Aug 7, 2005)

magic, what controller did you use

btw, this is a very interesting thread


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## magicmagni (Nov 7, 2003)

Controller?

Just a simple Digital timer from the local hardware store. Runs in one minute intervals.


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## Naja002 (Oct 12, 2005)

I just made 2 of these that have been running for about a week without a hitch. They are on 2 tanks side-by-side and run off of one double outlet air pump.

I use a digital timer to run the air pump for one minute. Each outlet goes to a 1 gal. Apple Juice/Gatorade jug. There is nothing restricting the flow except a check valve between the pump and the jug. I mix everything in the jug, except Phosphorous because it will cause precipitaion. Everything includes(Currently all SeaChem): N, K, Fe, Excel and Flourish. I have had no problems yet that I am aware of and there is no Growth, etc inside either container which are currently exposed to light.

Right now, the tanks contain Anubius, Crypts, Compacta Swords, E. tennellus, and things are booming.

What I have found is that because of Height/Head the system needs to be setup in the actual location that it is going to be used--Desktop gauging doesn't work well at all. It will pump a lot more fluid with a much weaker pump on a desktop than it will after its setup and has to battle Height/Head. Once You have built the system--set it up with the jug full of water and do the 1 minute increments to determine how many doses the system is good for in that particular setup/location.

Maybe someone can explain it to me, but in theory and in use--I don't see the need to go over the 1 minute increment on the timer. With an adequate pump, it will pump sufficient fluids in one minute. 2 minutes will just reduce the number of dosings the setup is good for by 1/2, thereby doubling the work required to maintain the system. Both of my setups will last 3 weeks (21 doses) before they become unreliable. So, I set mine up for that and I will only need to deal with ferts--once every 3 weeks. I am currently using the old-style $10 Whisper pump from wally world and it works great.

Finally, my 55 gal. is on a standard stand. I have found that moving the jug up directly behind the tank greatly reduces the Height/Head that the air pump has to work against allowing the use of a much less -powerful, -expensive air pump. The pump itself can be placed on the floor, but raising the jug helps tremendously. The 1 gal. Apple Juice/Gatorade jugs come with a sturdy carrying handle--I have mine hanging behind the tank on a small chain.

This system works Great and is just what I needed. The prospect of daily dosing long-term was just not very attractive to me at all. I love automation--always have.....

Many Thanx!


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## magicmagni (Nov 7, 2003)

Naja002 said:


> I just made 2 of these that have been running for about a week without a hitch. They are on 2 tanks side-by-side and run off of one double outlet air pump.


This is very exciting! I'm glad someone else has done this and has achieved similar results.



Naja002 said:



> I use a digital timer to run the air pump for one minute. Each outlet goes to a 1 gal. Apple Juice/Gatorade jug. There is nothing restricting the flow except a check valve between the pump and the jug. I mix everything in the jug, except Phosphorous because it will cause precipitation. Everything includes(Currently all SeaChem): N, K, Fe, Excel and Flourish. I have had no problems yet that I am aware of and there is no Growth, etc inside either container which are currently exposed to light.


That's great. It sounds like you are one step ahead of me. I am only dosing micros at the moment. Have to get off my duff and add the macro container... You may want to cover the containers though so that they are not exposed to light. The light can break down the ferts.




Naja002 said:


> What I have found is that because of Height/Head the system needs to be setup in the actual location that it is going to be used--Desktop gauging doesn't work well at all. It will pump a lot more fluid with a much weaker pump on a desktop than it will after its setup and has to battle Height/Head. Once You have built the system--set it up with the jug full of water and do the 1 minute increments to determine how many doses the system is good for in that particular setup/location.


Yes that is exactly right. If you need more days of dosing add more water. If you need less add less water. In some cases you can also mess with the digital timer, but I think more accurate results are had messing with the fill level in the containers.



Naja002 said:


> Maybe someone can explain it to me, but in theory and in use--I don't see the need to go over the 1 minute increment on the timer. With an adequate pump, it will pump sufficient fluids in one minute. 2 minutes will just reduce the number of dosings the setup is good for by 1/2, thereby doubling the work required to maintain the system. Both of my setups will last 3 weeks (21 doses) before they become unreliable. So, I set mine up for that and I will only need to deal with ferts--once every 3 weeks. I am currently using the old-style $10 Whisper pump from wally world and it works great.


That's great. I'm only doing one weeks worth, but I suppose you are onto something. The only reason I know one may want to run it longer is if they are also using this as a water level top off as well as a dosing pump although this requires larger containers obviously.



Naja002 said:


> Finally, my 55 gal. is on a standard stand. I have found that moving the jug up directly behind the tank greatly reduces the Height/Head that the air pump has to work against allowing the use of a much less -powerful, -expensive air pump. The pump itself can be placed on the floor, but raising the jug helps tremendously. The 1 gal. Apple Juice/Gatorade jugs come with a sturdy carrying handle--I have mine hanging behind the tank on a small chain.
> 
> 
> Great Idea!
> ...


I'm glad it worked for you!:thumbsup:


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## Ibn (Nov 19, 2003)

Good to see that you're still getting great results with these auto pumps that you set up, Jeff.

I went with the peristaltic pumps that Bill and Greg recommended (good $60 per pump spent). Makes it much more enjoyable to not worry about daily dosing nowadays.


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## magicmagni (Nov 7, 2003)

Funny didn't get an e-mail update when you responded Eric, but nonetheless that's great you got your dosing pumps. It sure is nice not to have to always be thinking of dosing during the week. I like doing all the maintainance one day each week so have the doser is great for that schedule. Now I just have to set one up for my ten gallon.

I did finally setup the macro portion of the doser. So that's been up and running for a few weeks now. Still working great without any problems.


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## Sietch31 (Feb 13, 2006)

Hello,

Jumping in the post, I am currently under testing of the same system !

That a great and simple idea !!!!
But those simple ideas are very often the more difficult to have !
Many thanks to you !!!
Automated dosing and auto top-off at the same time, I could not resist to test !

I am testing with a 1 gallon bottle, air pump and valve for air adjustment to the bottle. I am running the air pump per 1 minute steps and checking amount of water pushed in a scaled container.
I have set my test sytem with the same height/head as it will be when installed on the tank.

I have a question : when in use, the amount of liquid pushed to the tank is less and less each time, due to level going down in the bottle and time needed to build up the pressure....
For instance, if I set the air rate so that in the first minute air will push 270ml to the tank, after 10 times 1 minute (as if it was the tenth day), it will push only 150ml, and on the "20th day", it will push only 80ml (bottle is then almost empty....)

Did you face that problem ?
If yes how did you solve that to obtain a constant quantity of liquid injected ???

Thanks in advance for any thought on this....


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## magicmagni (Nov 7, 2003)

I never really noticed that, but I'd imagine that this is true. IME the time to build up pressure was minimal so much that I really didn't even factor it in. For my needs as long as the contents of the bottle were distributed to the tank by the end of the week I was happy. I use EI method of dosing and I don't buy into the whole mentallity that everything has to be so precise. This doser is probably not going to dose a constant rate. Does it matter? Not to my plants.


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## vidiots (Jun 17, 2006)

I would imagine that if it's consistancy your looking for you might want to try a couple of things. The variation in head height will change as fluid is dispensed which changes the pressure in the line and thus the flow rate. With any type of setup I think more head height in the tubing would help as well as a reservoir that is shallow with a large diameter. Picture this, if the starting height it has to pump the fluid is say 2 inches, and after a couple doses the fluid level in the reservoir drops 2 more inches. Now you have 4 inches of head versus 2 inches which doubles the back pressure and probably reduces the flow rate by 50%.

Now picture your starting height is say 24 inches that the pump has to raise the fluid. Again after a couple doses your fluid level drops a couple inches and now the head height is 26 inches. This time you only have an 8.3% change in the back pressure on the pump and the flow rate only reduces by 8.3% instead of the 50% in the first example and the only thing you changed was the height.

Now this is the catch to increasing the height, and that is the pump has to be strong enough to overcome the back pressure created by the head height.

Using a wide shallow container as the reservoir would also help by reducing the change in fluid level height per dose.

I think this is the reason my attempt at making one of these failed. I used a tall narrow bottle, had a very weak pump and had very little starting head height (just 4 inches). The result was very inconsistant dosing. I may take another crack at it though.


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## magicmagni (Nov 7, 2003)

Yeah that makes sense. I have a large tank so the distance from the doser to the top of the tank is about 5 feet so I guess a 5" change in fluid level is pretty insignificant, but perhaps more of an issue on setups where its closer? As far as pumps you do need a powerful one make enough pressure- most average "deep water" type pumps are fine.


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## Wasserpest (Jun 12, 2003)

I believe what Sietch experiences has nothing to do with increasing head pressure. The little humming pumps shouldn't be bothered by a few inches of head.

I think it is one out of two possibilities.

My bet is that somehow the gallon container is getting pressurized. This needs to be prevented. Air compresses, and the emptier the bottle gets, the more it will compress and as result you get less and less solution into the tank.

Make sure that the airline that transports the solution from the bottle to the aquarium is not restricted in any way. It should be open on the end, no nozzles or such which block the flow.

Another possibility would be an airleak at the cap. That would make a big difference for the ability to push the liquid out of a full or empty bottle.

Just my experiences... :smile:


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## vidiots (Jun 17, 2006)

Wasserpest said:


> I believe what Sietch experiences has nothing to do with increasing head pressure. The little humming pumps shouldn't be bothered by a few inches of head.
> I think it is one out of two possibilities.
> My bet is that somehow the gallon container is getting pressurized. This needs to be prevented. Air compresses, and the emptier the bottle gets, the more it will compress and as result you get less and less solution into the tank.
> Make sure that the airline that transports the solution from the bottle to the aquarium is not restricted in any way. It should be open on the end, no nozzles or such which block the flow.
> ...


With the air powered dosing pumps you can't get a pressure buildup in the bottle because you have a leak designed into the system. That leak is where the fluid comes out. The maxium pressure you can get above atmospheric with the pump off is equal to the head height of the output hose, which only changes with the fluid level in the bottle from one dose to the next unless you move the bottle or hose. If the pressure in the bottle were to exceed atmospheric pressure plus head height, fluid would flow.

What you do have increasing from one dose to the next is the volume that the pump has to fill with the pressurized air. Remember the pump is pumping air at a relatively consistant volume per minute. You use a timer to make sure your timing is consistant. At the start if you only have one cubic inch of air at the top of the bottle, then use the pump to add another cubic inch of air you have doubled the pressure inside the bottle which causes fluid to flow at a good speed. Now after several doses you have 10 cubic inches of air at the top. It now takes the pump 10 times as long to pump the bottle up to the same pressure/flow rate. What you tend to end up with is a time delay before fluid flows after the pump comes on, a slower flow rate as the bottle empties, but it also continues flowing for a longer time after the pump shuts off as this larger volume of air at a lower pressure equalizes with atmospheric. This is eventhough you have the timer on for a fixed amount of time.

As I was saying more head height on the output hose, a large diameter container, and a stronger pump should minimize these effects.


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## Wasserpest (Jun 12, 2003)

You are right. I was thinking more along the lines of my 20oz Gatorate bottles, but I guess in a gallon things might need more time to pressurize.

Still, restriction on the output, or simple air leak, will make things worse.


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## magicmagni (Nov 7, 2003)

That's a great explaination vidiots. BTW have you tried a differenct container yet? I have had good luck with some glass wine jugs that I had around. I believe they are 4L size. I have one for macros and one for micros. I like having the large reserve of liquid as it works as a auto top off as well and give me a lot of wiggle room to fine tune the level. If it empties a little too soon I fill it up a bit more. Not soon enough, I fill up a bit less. The delviery rate is pretty consisent too.

I just thought of something that may also contribute to the inconsistant doses. The Plastic bottle. Like you say once atmospheric pressure is exceeded the fluid flows out of the tube. This slight pressure buildup may be enough to "ballon" the plastic bottle just enough to cause issues -they are really flexible. Instead of the plastic bottle a glass one would be better as there is no chance of compression and expanson to influence dosing volume.


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## kzr750r1 (Jun 8, 2004)

magicmagni said:


> That's a great explaination vidiots. BTW have you tried a differenct container yet? I have had good luck with some glass wine jugs that I had around. I believe they are 4L size. I have one for macros and one for micros. I like having the large reserve of liquid as it works as a auto top off as well and give me a lot of wiggle room to fine tune the level. If it empties a little too soon I fill it up a bit more. Not soon enough, I fill up a bit less. The delviery rate is pretty consisent too.
> 
> I just thought of something that may also contribute to the inconsistant doses. The Plastic bottle. Like you say once atmospheric pressure is exceeded the fluid flows out of the tube. This slight pressure buildup may be enough to "ballon" the plastic bottle just enough to cause issues -they are really flexible. Instead of the plastic bottle a glass one would be better as there is no chance of compression and expanson to influence dosing volume.


The only thing I'd worry about with glass is exploding.

Takes me back to the third of July a while back like 1982 or so.

Three kids find an empty gallon wine bottle with the cap. Three kids decide it's a great idea to place a lit spinning flower fire work inside the bottle and spin the cap back on.

Now to this day will not know if it was temp or pressure or both that made the bottle explode but it was impressive... At the middle of the burn I ( yeah ) told the other two to turn away. Pop. Little brother had a little shrapnel in his leg and that was all. We were lucky to say the least.

Sorry for the flash back but it's the 4th and my dog is freaking out. We live next door to the largest park in town and everyone is out setting off there works.

At some point having some expansion to deal with will be better served encasing a container in a foam brick. Depending on the size making a cardboard form to place the containers in and spray in the foam. It will expand around the containers and in the same swoop insulate and keep the light from the solutions.

I'll have to try this with 2 liter bottles... See what happens. Since there are two bottles of pop here at the house today it's time to try this method. I'm going to the garage and find the air pump.


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## magicmagni (Nov 7, 2003)

Well we are not putting fireworks in the glass here LOL. This is only air and likely not more then 10psi if that. Most glass beverage bottles are pretty thick so they don't break in shipping. I think you would have to have about 100psi or more on there before there is a chance of anything happening and even then I think the hose connection that you glue on the cap would pop off before the glass did anything.

I you are very paranoid though you could go ahead and take some packaging tape and wrap the whole bottle with it. This way here if it breaks it will contain the glass- sort of like the windshield on your car. I can say I have run this system for a very long time now and never had a problem or even a hint of one in this regard.


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## crazie.eddie (May 31, 2004)

What's the brand/model of the 1 minute digital timer you bought? I've been looking around for similar timers and all I can find are cooking timers.


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## vidiots (Jun 17, 2006)

crazie.eddie said:


> What's the brand/model of the 1 minute digital timer you bought? I've been looking around for similar timers and all I can find are cooking timers.


I bought the Radio Shack Home Automation Starter Kit for around $40. It came with a digital timer that be programmed and can controll up to 8 devices. It has remote modules that the devices plug into. The timer/controller is battery powered but plugs into the wall to send signals through the power circuit to the modules. The timer and all the modules have to be plugged into the same electrical circuit to work. It worked beautifully for everything except one. That was the large external balast for my three 175watt Metal Halide lamps. The balast generates too much electrical noise for the modules to be able to receive the signals from the controller correctly while the lights are on. To work around this I put the lights on a mechanical timer, and scheduled all the other devices to switch on and off while the lights are off. By the way the system works great for regular flourencent aquarium lights even the lamp module which is not supposed to work well with flourescent lighting.


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## vidiots (Jun 17, 2006)

kzr750r1 said:


> The only thing I'd worry about with glass is exploding.


I agree that it would take a lot more pressure to break a wine bottle than the average aquarium air pump can generate. These bottles are designed to hold a lot of pressure generated by the yeast CO2 caused by the wine fermenting inside, and would probably be ideal for DIY yeast CO2 generators. Your air line tubing would burst or come appart long before those bottles ever did.


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## kzr750r1 (Jun 8, 2004)

Yeah Yeah Yeah..,.. I understand it's only 10 PSI or less and it can go higher without an issue. This just brought up a bad memory... It was the 4th. 

The top would probably leak before it burst even at 100 psi, but I’m not going to experiment to that point.

My life is full of past mistakes. I’ve had go cart rims explode on me not knowing that the air hose had 150 PSI on tap. Lucky to still have my left thumb after that one, say it with me, PAIN. We all learn from mistakes and keep mental notes not to repeat. Cross reference pain (mental or physical) and recall something that could save others the same. All I was trying to convey. Just be careful. K.


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## magicmagni (Nov 7, 2003)

Just keep living to tell!

On the timer. This is the one I use. Has battery backup so you never have to reprogram it after a power outage.

http://www.rewci.com/insedaydiprt.html


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## vidiots (Jun 17, 2006)

magicmagni said:


> Just keep living to tell!
> On the timer. This is the one I use. Has battery backup so you never have to reprogram it after a power outage.
> 
> http://www.rewci.com/insedaydiprt.html


What do you think of that timer? I've considered getting some of those. The part that stopped me is that I'd need like 7 of them and at $23 each that adds up quick. The only other think I don't care for looking at the picture is the amount of outlet space it takes up.

Ideally what I'd like to someday find is a power strip where all of the outlets could be independantly controlled by a single built in programable digital timer similar to the one you have.

I know that coralife makes a digital power strip, but the outlets are not all completely independant.

That way everything could be controlled by one device, lights, water changer, auto doser, CO2 solenoid, etc.


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## magicmagni (Nov 7, 2003)

It gets the job done. If I did it again I would have used them for all my timing needs on my tanks. What would be really nice for this application (as far as really fine tuning easier) would be a timer that you can set by the second and not the minute, but it's all good.

As far as outlet space what you can do is get a short extension cord, like say 1 foot and plug the timer into that.

Wow why do you need so many timers? Do you have that many planted tanks?


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## kzr750r1 (Jun 8, 2004)

It is a good unit with a lot of flexibility, nice to not have to re set each power outage... The plug placement is problematic but can be overcome with some handy work or trick side mounted receptacles on a power strip. Making pig tails is simple too. Just make mini extension cords from your power strip.


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## vidiots (Jun 17, 2006)

magicmagni said:


> It gets the job done. If I did it again I would have used them for all my timing needs on my tanks. What would be really nice for this application (as far as really fine tuning easier) would be a timer that you can set by the second and not the minute, but it's all good.
> 
> As far as outlet space what you can do is get a short extension cord, like say 1 foot and plug the timer into that.
> 
> Wow why do you need so many timers? Do you have that many planted tanks?


I too would like to see timers that can be set in seconds.

I've had to do the extension cord thing for a few things too. Just looks neater without them.

Actually I only have 3 tanks with plants in them. My light fixture over my 180gal tank has 4 seperate power cords for independant control of the lighting. I currently have all 4 pluged into a power strip that is pluged into a timer. I'd like to have them on seperate timers so that I can stagger the lighting thru the day and do the sunrise/sunset effect. I was also thinking of adding some moon lights which would require another timer.

The automatic water changer on my 180gal tank is on a timer. I'd also like to put my CO2 controller on a timer that shuts the CO2 off at night, to save on CO2 refills.

I'm still working on an auto doser that I am completely happy with, and if I use an air or liquid pump that will need yet another timer. I want good consistancy and high reliability with my auto doser. The liquid pump method shows promise especially if I use a large reservoir. I'm also gonna test the gravity feed drip method, thinking simpler might be cheaper and more reliable with fewer things to go wrong.

I'm not to concerned with timers for the other two small tanks, just to turn the lights on and off for them. They are not really display tanks, just a place to temporarily store the excess plant clippings and fish fry until I deside what to do with them.


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## magicmagni (Nov 7, 2003)

Yeah I use a lot of timers too. I have 3 banks of lights on the 120gallon that come on in stages via the 3 timers, then the timer for the doser.

There's probably something out there that will control everything for you, but if probably costs a lot.


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## scolley (Apr 4, 2004)

*X10 Automation*

If you have a LOT of timers... then this is a pretty awesome and cost effective little tool. The company selling it is too goofy for words, with all their obnoxious advertising. But if you can get beyond that, you lay down $50 for a some PC software that lets you set up as many, wickedly sophisticated, timers that you want. You then download the timers into a little module through your PC's USB port. You plug that into the wall and it executes all the multiple timers you've set up. But the catch is that you have to have purchased an X10 lamp or appliance module for each thing you are controlling. The little x10 modules cost from $5 (Internet sales) to $14 (radio shack), depending on where you get them.

But it works great. I've got timers on my CO2, UV, 4 different banks of lights, an air pump, a valve that drains my tank, and a pump that fills it, and lots more.

It's worth a look if you've got lots of timers IMO.


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## magicmagni (Nov 7, 2003)

Wow that is too cool! Endless possibilities there!
:thumbsup:


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## vidiots (Jun 17, 2006)

scolley said:


> If you have a LOT of timers... then this is a pretty awesome and cost effective little tool. The company selling it is too goofy for words, with all their obnoxious advertising. But if you can get beyond that, you lay down $50 for a some PC software that lets you set up as many, wickedly sophisticated, timers that you want. You then download the timers into a little module through your PC's USB port. You plug that into the wall and it executes all the multiple timers you've set up. But the catch is that you have to have purchased an X10 lamp or appliance module for each thing you are controlling. The little x10 modules cost from $5 (Internet sales) to $14 (radio shack), depending on where you get them.
> 
> But it works great. I've got timers on my CO2, UV, 4 different banks of lights, an air pump, a valve that drains my tank, and a pump that fills it, and lots more.
> 
> It's worth a look if you've got lots of timers IMO.


I'm also looking into the filters for the X10 modules, so that they will work with my lights. I really like the ones I bought from radio shack. They work with everything but the ballast for my large metal halide lamps, maybe the filters will fix that.


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## scolley (Apr 4, 2004)

My apologies magicmagni, if this is a hi-jack. I'm sure you do not want this to turn into an X10 thread! But before everyone gets too excited, I need to add in a few caveats about using X10 for scheduling events.

1) *You have to be able to accept failure *- X10 signals are sent through your house electrical wiring. There can be interference (there are ways to mitigate this), signal degradation, or even power failure that causes an event signal to not be received by the X10 module. For example, it you turn a light on, and then lose power 8 hours later when the "turn light off" signal was supposed to be sent, when the power comes back the light will just remain on until the next scheduled "light off" signal.

2) *You have to prepare for spurious signals *- X10 rarely has a false alarm, but power surges and/or someone turning on/off the controlled device will trigger a "Turn on" signal for that device. For example, a light could be properly turned off by the X10 module (the light itself is switched on, but the in-line X10 module is letting no power through). But you flip the light switch off than on and the X10 module will actually turn the light on (thinking you wanted it on)! This can also be caused by a power surge.

This only happens to X10 modules with "local control" logic, like the Radio Shack modules. You can buy different modules, or disable it (as I do) using these instructions.

X10 is nice, but it's not perfect. I have autodosing, but I do not control it with X10 modules at the moment, because I cannot afford the possibility of losing power during dosing and the "dosing off" signal not happening and over dosing the tank when power returns. I haven't tested that yet.

Technically the control module I pointed out in my prior post has battery backup. So it should be able to turn X10 modules off when you have a power failure. I just haven't shut the power off at my house's fuse box to test it.

So maybe should not have brought it up in a dosing thread. Sorry. I was inappropriately responding to the "needing a lot of timers" comments. It is not appropriate for dosing timers IMO. A temporary power outage causing your lights to stay on all day is one thing, dosing for 24 hours is something else entirely.


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## vidiots (Jun 17, 2006)

*Head Height versus Flow Rate*

Since there were some questions about my questimate as to how much the fluid head level effected the flow rate and my figuring of more head height being better, I desided to put my thoughts to the test.

I used a gravity feed drip system to conduct the test. First I mounted the reservoir 5.5" above my sump and adjusted the drip rate which remained at the same setting for the remainder of the tests. I measured the drip rate using a stop watch in drips per minute, with the reservoir low on fluid and again with the reservoir full of fluid. A change in fluid level in the reservoir bottle of about 4 inches.

Second I mounted the bottle at a height of 29 inches above my sump and repeated the above test.

The results suprised me a little. Instead of there being a 1:1 corelation between a percent change in head height to percent change in flow rate the corelation was about 1:2. This means that a 10% decrease in Height above the sump decreased the flow rate by about 20%. However I was dead on with the asumption that having the bottle mounted higher results in a much smaller difference in the empty versus full flow rate.

I have desided with these results that I am going to keep my bottle at the 29" height. The % change in flow rate at this height is about 25% Empty versus full reservoir. I figure I will just measure the two after setting it, and average them and should be able to keep my dose rate constant to within ±12.5%.

If I were to keep my bottle at the 5.5" height my dose rate would vary by ±30% of the average.

Hope this information is useful to those designing their own auto dosers.


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## kimo (Jul 15, 2006)

vidiots said:


> With the air powered dosing pumps you can't get a pressure buildup in the bottle because you have a leak designed into the system. That leak is where the fluid comes out. The maxium pressure you can get above atmospheric with the pump off is equal to the head height of the output hose, which only changes with the fluid level in the bottle from one dose to the next unless you move the bottle or hose. If the pressure in the bottle were to exceed atmospheric pressure plus head height, fluid would flow.
> 
> What you do have increasing from one dose to the next is the volume that the pump has to fill with the pressurized air. Remember the pump is pumping air at a relatively consistant volume per minute. You use a timer to make sure your timing is consistant. At the start if you only have one cubic inch of air at the top of the bottle, then use the pump to add another cubic inch of air you have doubled the pressure inside the bottle which causes fluid to flow at a good speed. Now after several doses you have 10 cubic inches of air at the top. It now takes the pump 10 times as long to pump the bottle up to the same pressure/flow rate. What you tend to end up with is a time delay before fluid flows after the pump comes on, a slower flow rate as the bottle empties, but it also continues flowing for a longer time after the pump shuts off as this larger volume of air at a lower pressure equalizes with atmospheric. This is eventhough you have the timer on for a fixed amount of time.
> 
> As I was saying more head height on the output hose, a large diameter container, and a stronger pump should minimize these effects.


If you could find a thick walled balloon of the proper size to fit in the bottle (those kid's balloons lose too much air due to leakage), then the balloon would expand as the fluid was used, keeping pressure (and volume) in the bottle the same, and fluid delivery the same over the whole dosing period.


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## CardBoardBoxProcessor (Sep 17, 2006)

Well... does this system work? I though of doing the same thing.. my question is.. how do i mix the ferts in? how do i know it gets the right does? see how much water comes out in 1 minute and for every ammont of that i add the needed dose for that day?


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## CardBoardBoxProcessor (Sep 17, 2006)

oh.. the whole presure thing.. you would need a container of water with a back stop valve that leads into a bladder inside the container that is being presurized. thus.. the new space is filled and it is not diluting the solution.


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## magicmagni (Nov 7, 2003)

CardBoardBoxProcessor said:


> Well... does this system work? I though of doing the same thing.. my question is.. how do i mix the ferts in? how do i know it gets the right does? see how much water comes out in 1 minute and for every ammont of that i add the needed dose for that day?




Very simply. Just decide how much water (size container) you want to work with. I'd say go with as large as a container as you can.

Take what you would normally dose in one week or two weeks or 3 weeks (however long that you want it to last for) and put it into the dosing container. Time it out with the timer so that it empties the contents over the amount of time you want. You can fine tune it with the amount of water you add to the container. Does it empty too fast? Add more water. Too slow add less. You can also play around with the time the timer leaves the pump on for. Try 1 mintue instead of 2 for example if it's going too fast.

Use plain water at first untill you get dialed in. Then add the ferts once you know it's working correctly.

Ferts may settle a bit in the containers. This can be countered by putting an airstone in the container. This will mix up the solution everyday a bit. Oxidation should be minimal since it's only on for a minute or two max.


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