# Indigo's Fertilizer Autodosing System (56K)



## Gatekeeper (Feb 20, 2007)

Very nice setup indeed sir. I have to agree with the two separate lines into the reactor for dosing. I myself have not setup an autodosing method yet, but will in the next few months once I figure out what method of dosing works for me.

With regards to the AC jr, ironically enough, mine just came in the mail for me. I honestly went this route for the reasoning you have, I hate the stupid timers. I have had two timers burn out on me in the last 6 months and luckily it was not on my Fill solenoid on my auto water changer or that could have gotten real ugly real fast (considering that the one timer actually froze with power on...figure that one out).

Well done though.


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## lescarpentier (Feb 2, 2008)

Judging by the loneliness of this thread,I think that most people,like me,are scratching their heads in bewilderment.However,I am favorably impressed,and know that eventually I will be implementing a system such as yours.Thank you for taking the time to share this with us,and for the honest,and frank assessment of your efforts.This is remarkable!

Now for my questions.
How much does this system cost to set up?
Are there any kind of safeguards to prevent over fertilization,other than continual monitoring?

I look forward to any periodic updates.

Once again,thanks.


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## imeridian (Jan 19, 2007)

There's a lot more risk of under fertilizing than over, really. The timer problem mentioned earlier has resulted a couple of times in no fertilization happening that day -- which is a big reason for my switch to daily dosing of both micros and macros. If I miss half a dose it isn't so bad. The pumps won't allow any fluids through unless they're powered on.

As for cost... a lot? Each pump is roughly $80, tubing is $.40 a foot, though I'm sure one could use regular inexpensive stuff instead. Figure in probably $10-15 for fittings, check valves, and miscellaneous stuff, and a ridiculous $20 for each timer (and, really, I'm so disgusted with these timers). I've never added it up... and, well, I won't either.  

Heh, threads I start are usually lonely... *shrug*

I've been thinking of setting up a sort of 'mini reactor' inline after the main CO2 reactor, just a series of injector ports on 3/4" pvc. It'll cost a lot less than redoing my reactor, and the lab tubing just isn't sturdy enough to be drawn directly through the pipe wall like tygothane or norprene is. I stacked 4 tees together for 2" pvc the other day at Lowes and it's a bit too huge for my liking. The 2" pvc would be also upgrading my CO2 reactor, as the 1.5" appears to not be quite large enough, still get micro bubbles. I don't mind the bubbles so much, but I figured if I was redoing the reactor for one reason, I might as well redo it for another while I was at it.

When it really comes down to it though, apart from the timer problem and realizing I could improve the actual injection, I'm quite satisfied with how this has been working for me. Consistency has always been a big problem for me when it comes to dosing. Since I've switched to autodosing my plant growth has improved remarkably.

Oh, and thanks Glenn, especially for sharing my pain (lol) over bad timers.


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## epicfish (Sep 11, 2006)

Nice work!


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## EdTheEdge (Jan 25, 2007)

A true hobbyist.... I salute you!


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## Gatekeeper (Feb 20, 2007)

I am curious which timers you are having problems with and if they are the same as mine. 

Did you use the H202 bottles for any particular reason or just had them laying around?

What kind of volume are you dosing and what are your turnover rates from your solutions? (ie how many doses per bottle)


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## imeridian (Jan 19, 2007)

They're the grasslin digital timers from DFS. 

I used H202 bottles intentionally. They're HDPE, so stable over the long term, and opaque so as to prevent any long term light damage. It was just easier to pop over to walmart, pick them up, dump the h2o2, than to order appropriate bottles.

The macro bottle holds approximately eight weeks of solution. With the daily dosing, the pumps run between 15 and 20 minutes (micro/macro), delivering 7-10ml of solution. 

I'm basically using the same solution I used to mix up and dose using a 25ml graduated cylinder manually, and I know it's good for that long (except the one time I left it mixed in the erlenmeyer flask on my desk -- I grew some very interesting things in it that time). The Flourish Comprehensive is at 100%, no dilution, so it's more a matter of just pouring it from the 2L jug into the 500ml bottle. 

The 1L bottle is changed weekly, as I dose 150ml per day over the week of 'topoff' (aka line flush). 

I did recently cut down from dosing 25ml of macro 3X weekly to dosing the 10ml everyday. That extended my solution longevity to 8 weeks from about 6.5. Now, since none of that really means a lot, here's what my macro mix is:

Macro Mixture: 500ml total volume with RODI Water
92g KNO3, 8g KH2PO4, 25g K2SO4

25ml = 9.94ppm N, 0.98ppm P, 8.65ppm K

My macro mix is also sort of a work in progress, I've only recently added the extra K.


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## Gatekeeper (Feb 20, 2007)

75 gallon tank?

So your flush line is simply to flush out the dosed mixture daily? Now, do you account for the excess "stuff" left in the tubing that is flushed into the tank? Did you calculate that somehow (ie the volume of ferts that is in the line once you dosing pump stops)

interesting concept with the H202 bottles. Never thought of using them.


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## imeridian (Jan 19, 2007)

Yes, 75 gallon tank.

There really isn't any 'excess' to account for. The outflow line from the pump stays 100% full, in addition to the inflow line to the pump. When the pump is on, it's basically dripping out of the check valve right into the 'flow line system' with all the connections. Well, there is that tiny bit of tubing that connects the checkvalve to the 'flow line' but it's so tiny (and hidden with electrical tape in the photo) that I don't worry about it. 

The flush line is, yes, just that, there is a short space there where the two fluids may meet, I use the 'topoff' pump to flush that. I used to have the pumps (and all connections) on the other side of the stand, thus there was a lot more need to flush the line (since it was 4' long), now it's much less important and part of the reason for the pump move too. 

I think once I get a larger volume container setup for the topoff that I'll run that pump for the entire period the fert pumps are running. It's interesting to watch the fert pumps run, because it just basically squirts out little droplets in the line, spaced with a vacuum "bubble."

Those piece of crap grasslin timers reset themselves again sometime today, just the two fert pumps, yesterday it was just the macro pump. I'll need to do something about the timer situation immediately, it can't wait for the AC jr. Well, maybe I'll order it within the week instead of "eventually" as planned. I wish I knew why the timers were resetting randomly.


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## Wasserpest (Jun 12, 2003)

I have a wild mixture of electronic timers and they are all working extremely well. There are different GE timers, Intermatic, but no Grasslin. Do you have power outages that make those timers reset? 

I am to cheap for the AquaController, but I am wondering if an Irrigation Timer (~$20) could be tweaked to control pumps. Maybe the 12V output could control relays that switch the pumps. The model I am thinking of has 4 zones -- one could run the first zone (macros) for a few minutes, then the second zone (main lights) for 10 hours, then the third zone (moonlights) for two hours, then the fourth zone (micros) for a minute. Hmmm... there is an idea.

I tweaked a little delay timer circuit to switch my pumps in the second instead of minute range, and it can be connected to the light timer or to one of those cheap mechanical timer things. The AC is definitely nicer though.

The drop of methylene blue is a great idea, need to try that.

Instead of topping off via the expensive peristaltic pump, you could probably get a $15 waterpump and use that one to top off in a minute or what.


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## imeridian (Jan 19, 2007)

It isn't power outages or any other surges that I'm aware of. The UPS on my workstation and file server will send an email as the result of any power event. Perhaps it's excess EMI from all the cords under the stand, it's very random. The one pump would reset everytime I pressed the manual 'bypass' button, I exchanged that one. The other two I've had too long to do anything about, other than just replace with something else. They have NiMH rechargeable batteries inside that protect against power outages, supposedly, I can unplug the timer and it keeps the time; that's how I program them. 

Yes, the topoff pump is sort of... one of my boneheaded choices. I've thought of switching it to something else, but I'm not really sure what. It all stemmed from my original idea of using the float switch, which triggered the relay, etc, and it'll just topoff slow over the course of the day as needed. The float switch idea fizzled, so... I've made do without any real automatic topoff.

Yes, the price of the AC Jr is a real sticking point for me. I look at it how I look at everything else though... if it'll solve my problem, it'll be worth it. I don't know how many other brands of timers and such I'll need to go through until I find a workable solution. 

The Methylene blue idea comes from Ed over at APC, I'm sure 'weird things growing' is much greater a problem with the seriously diluted PPS solutions.

Is this the sort of irrigation timer you were referring to?


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## plantbrain (Dec 15, 2003)

indiboi said:


> There's a lot more risk of under fertilizing than over, really.


Well, is it any more reliable than human dosing?
I think you can find the motors for these are really cheap(10$), low RPM telescope motors on ebay.......

DIY the pumps my friend

But if you like auto dosing, why not add sediment ferts for another level of back up and reduntacy?

Regards, 

Tom Barr


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## imeridian (Jan 19, 2007)

Tom, once I get the timer issue worked out, the pumps are more reliable than me, without question, lol. One of the main driving forces for this system was that I have a very irregular sleep schedule. The inconsistency of my manually dosing was really taking a toll on my tank. 

I have Eco Complete as the substrate in this tank, someday I'll add some of the Seachem root tabs I've bought. I haven't put them in because I just don't see the need. 

There are a good many examples of how to do this for less money already, Wasserpest, especially, has numerous examples of really ingenious ways of doing this sort of thing. Mine is more of an example for someone that wants to use more 'off the shelf' type components.

Heh, judging from the sounds made by fellow amateur astronomers' telescopes (fork mount SCTs in particular) those motors would wake the dead if used inside. I prefer people power for my telescope, haha, yay dobsonian mount!


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## Wasserpest (Jun 12, 2003)

indiboi said:


> Is this the sort of irrigation timer you were referring to?


Yep, this sort of thing. The lowest priced 4 zone controller costs about $20 (in HD at least) and includes transformer and battery backup and all that.


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## imeridian (Jan 19, 2007)

Well, I'll leave that in your capable hands to figure out how to make it all work for our purposes...  I'd seen those timers before, but didn't realize just how they worked. I don't suppose there's much difference between it triggering a solenoid and having it trigger a relay.


I did some testing of the pumps tonight, and it appears that regardless of which grasslin timer it is pugged into, the SP200 15ml/min pump has a very high likelihood of resetting every timer whenever it clicks on or off. It seems there's some sort of surge, as it is also clicking my heater on/off. This does not seem to be the case if the SP200 pump is plugged into a Coralife digital power strip. Hopefully that'll solve the problem in practice. I suspect I'll just bite the bullet and buy that AC Jr.


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## AndrewH (Dec 24, 2007)

First off, please forgive my lack of knowledge when it comes to ferts. Up until now I've been growing easy, low light, no fuss plants and avoiding the whole "ferts" subject as much as possible  though I have read some of the theories behind dosing ferts (and agree with them).

The system looks really well designed and I can tell a lot of thought went into each detail, but I have a few questions.

1. Why are you dosing so slowly? Why not just shoot all of the ferts in one shot? Is it to help evenly distribute the chemicals or for exact dosing?

2. If you're dosing everything daily, why not have one solution with the micros and macros together?

3a. What about having the dosing system in the canopy? That way you're just letting gravity move the liquid and all you're doing is opening and closing the line (with a solenoid), basically eliminating the $80 pumps? You would need a control nozzle to only allow X amount to flow at a time, then use a timer to control the solenoid opening and closing, but that would get the job done without having to use a pricy pump, right?

3b. Or even use a really slow drip nozzle so the ferts are falling into the tank 24/7 (no solenoid needed). Figure out the amount you need each day, find a drip nozzle that will equal that amount over a 24 hour period and let it run all of the time. Simply keep a second bottle of micros and macros ready to go for when the ones on the tank run dry and change 'em out.

4. What about adding a couple of ports to the inlet side of the canister's hose? This would allow the canister's inlet negative pressure to draw in the ferts. Simply have the fert hose controlled by a solenoid and a timer.


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## Gatekeeper (Feb 20, 2007)

> 1. Why are you dosing so slowly? Why not just shoot all of the ferts in one shot? Is it to help evenly distribute the chemicals or for exact dosing?


This is the way the pumps work. They are not speed regulated, they are set to deliver a preset volume per time, so they are extremely accurate.



> 2. If you're dosing everything daily, why not have one solution with the micros and macros together?


I believe there is some voltility in doing this, but I can't quite recall the exact reasoning... Indiboi?



> 3a. What about having the dosing system in the canopy? That way you're just letting gravity move the liquid and all you're doing is opening and closing the line (with a solenoid), basically eliminating the $80 pumps? You would need a control nozzle to only allow X amount to flow at a time, then use a timer to control the solenoid opening and closing, but that would get the job done without having to use a pricy pump, right?


Why put something in the canopy when you can plumb it into the stand? This is a matter of preference, but I like having as much equipment as possible in the stand and I think Indiboi has the same line of reasoning. $80 for a pump isn't so bad, its solid equipment and reliable.



> 3b. Or even use a really slow drip nozzle so the ferts are falling into the tank 24/7 (no solenoid needed). Figure out the amount you need each day, find a drip nozzle that will equal that amount over a 24 hour period and let it run all of the time. Simply keep a second bottle of micros and macros ready to go for when the ones on the tank run dry and change 'em out.


I guess this is possible, but there is some chance of clogging since the drip would be so slow. 



> 4. What about adding a couple of ports to the inlet side of the canister's hose? This would allow the canister's inlet negative pressure to draw in the ferts. Simply have the fert hose controlled by a solenoid and a timer.


This is basically what he is doing, but its on the outlet of the pump. Letting the pump draw it in will have some back pressure on the line, thats why the pump selection is critical.


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## Wasserpest (Jun 12, 2003)

You can't mix macros and micros because the phosphate reacts with the iron, resulting in a shower of FePO4 which makes both nutrients unavailable to plants.

You could leave the K2PO4 out of the macros and then mix them. I found it is better not to mix them anyway as there is always a chance for some reaction and settling of the mixture.

Having the fertilizer reservoir in the canopy sounds like a more complex solution, besides most canopies are heavy enough. Solenoids aren't exactly cheap either... And connecting this to the inlet of the filter sounds like a good idea until it sucks air for some reason.

I found that with the APT pumps there is a little bit of flow even if the pump is not running. Putting them on the filter outlet allows to use a simple check valve to prevent backflow. On the inlet that would be difficult to solve.


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## imeridian (Jan 19, 2007)

gmccreedy and Wasserpest, thank you, you gave basically the same answers that I would have. 

I chose this method of dosing as I found it to be the most elegant solution to the problem. It costs what it costs. There are many ways to do it for less, and even a few where it'll cost even more.


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## Johnnnn_h (Apr 14, 2007)

Thank you for posting pics and info!! 
I picked up a pair of 1ml per min APT peristaltic pumps, & needed to find info on hoses and checks.


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## imeridian (Jan 19, 2007)

I'm glad my post has been helpful for you.


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## fishscale (May 29, 2007)

Man, I am so jealous right now. Those pumps are pretty expensive, though. Like 65 bucks each?


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## imeridian (Jan 19, 2007)

I wrote out $80, but that was a bit of an over-estimation. $65 is correct, add another dollar or so for an extension cord & wire nuts (or pay $6 for them to put the plug on).


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## Wasserpest (Jun 12, 2003)

Plus shipping of course. And a long time of waiting... :eek5: 

Just a word of warning... I bought two of those pumps, and the 15rpm one kept stripping the little plastic rotor. Not sure why. Got some replacement rotors, which stripped after a while too. After half a year on and off I ended up getting a replacement pump which works for now.


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## imeridian (Jan 19, 2007)

Don't know if the one you were having problems with is the SP200 or SP100, but I wouldn't recommend the SP200 series, since it has mostly plastic pieces. The SP100 is mostly metal, so it should be more durable. It seems APT is one of those companies that you need to nag a little once you've placed an order. About a week after I ordered I hadn't received word of it being shipped, emailed, and then they were shipped that day (without any response to the email). 

As a follow up, my timer resetting problem was indeed resolved by putting the SP200 pump on the Coralife digital timer/power strip, but still using the Grasslin for the two SP100 pumps. I had only recently put the SP200 onto a Grasslin timer, and apparently they're just not compatible.


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## original kuhli (Nov 28, 2006)

Have you had any precipitation in either of your fert reservoirs? Do you think mixers are necessary?


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## imeridian (Jan 19, 2007)

I haven't had any precipitation in the reservoirs, the solution is basically the same that I'd used before the pumps. As long as one keeps the mixture within the range of solubility at room temperature it should be fine. Now, mixers are indeed important if one is dosing something like a GH slurry. 

The only weird thing I've noticed is that the color of Methylene blue seems to settle toward the bottom, I don't really think it's necessary so I'm not going to include it in my next mix. This may be an artifact of my recent addition of extra K, which brings the whole mixture close to the solubility limit. I'll probably drop the extra K too. It was a bit of a questionable thing to do anyway, since I didn't increase the water volume.


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## Wasserpest (Jun 12, 2003)

indiboi said:


> Don't know if the one you were having problems with is the SP200 or SP100, but I wouldn't recommend the SP200 series, since it has mostly plastic pieces. The SP100 is mostly metal, so it should be more durable.


It was a SP100. The little plastic rotor didn't last. I think maybe due to a badly aligned shaft.


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## original kuhli (Nov 28, 2006)

I'm a bit concerned about the salt settling to the bottom giving you a stronger concentration of fert intitially and a weaker concentration later in the batch...your methylene blue could be illustrating that...


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## imeridian (Jan 19, 2007)

I used this solution (not counting the new addition of extra K) before I put it into pumps, it was fine for the year before the pumps. Simply using the pump to do it instead of measuring it myself won't be a dramatic difference. I haven't had any issues with this current batch as far as my levels being off (been testing N & P levels since I made the change in K dosing to verify that). 

I am going to remove the extra K from the dosing, like I mentioned earlier, just because I know it's pushing the limits and it's not really necessary anyway, but I could easily add extra water to help better keep the K2SO4 in solution instead (adjusting dosing time of course to compensate). In that regard I agree, the solution is a bit more dense at the bottom where it's taken up by the pump. It's just at the edge of staying in solution, so with a little swirl every week it's okay. I only have maybe two weeks left to go anyway.

If it makes you feel any better, I mixed up the solution (minus the meythlene blue & extra K) and let it sit on my desk in an erlenmeyer flask for months to see what would happen. It did grow an interesting little fungus, but otherwise no settling. So, while I understand where you're coming from, I've thought this through and I'm not concerned.


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## Gatekeeper (Feb 20, 2007)

I have seen many people doing this, its nothing new and as long as the solution is dilluted and mixed properly, it has never caused issues that have been expressly stated.


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## imeridian (Jan 19, 2007)

Indeed, one just needs to make sure the solution is stable at the temperature it'll be stored. I goofed a little when I added the K2SO4 to my solution without adjusting the water volume, it's just a bit too close to the limit when at 75 degrees in my stand.


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## original kuhli (Nov 28, 2006)

Cool, thanks...the last thing I wanted to do was add a stirrer to my already silly bill for autochanging and dosing...


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## imeridian (Jan 19, 2007)

No problem. I like to keep my solutions extremely concentrated, as I believe it helps prevent weird things from growing, but care does need to be taken so as to not make them so concentrated they fall out of solution.  If you stay far enough away from the limit they will stay in solution indefinitely. 

Hehe, I'd put a stirrer on the list anyway, I'm eventually going to get one. Every couple of months I go to ebay, put one in my "watch list" and then I don't buy it. I can imagine mixing things up to be so much easier, but it's hard to justify the $80 for something I can do myself by shaking the flask.


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## AndrewH (Dec 24, 2007)

gmccreedy said:


> This is the way the pumps work. They are not speed regulated, they are set to deliver a preset volume per time, so they are extremely accurate.
> 
> I believe there is some voltility in doing this, but I can't quite recall the exact reasoning... Indiboi?
> 
> ...





Wasserpest said:


> You can't mix macros and micros because the phosphate reacts with the iron, resulting in a shower of FePO4 which makes both nutrients unavailable to plants.
> 
> You could leave the K2PO4 out of the macros and then mix them. I found it is better not to mix them anyway as there is always a chance for some reaction and settling of the mixture.
> 
> ...





indiboi said:


> gmccreedy and Wasserpest, thank you, you gave basically the same answers that I would have.
> 
> I chose this method of dosing as I found it to be the most elegant solution to the problem. It costs what it costs. There are many ways to do it for less, and even a few where it'll cost even more.


Ahhh, those answers make since to me. I guess my reasoning for wanting to put the ferts in the canopy were to use gravity to my advantage instead of trying to overcome it , but like you said getting a clog would stop the ferts all together.

I think my other idea regarding putting the inlets from the ferts onto the inlet of the canister was to also reduce the amount of total equipment, but again I didn't realize the fert amounts needed to be as accurate as possible .

I'm getting solenoids for $30 each (for 1/4" or 3/8" tubing ) .

Well I certainly appreciate you taking the time to explain the design details to me. I definitely like the design and plan to use it (or something like it).


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## Gatekeeper (Feb 20, 2007)

AndrewH said:


> I'm getting solenoids for $30 each (for 1/4" or 3/8" tubing ) .


What are you planning on doing with those? A water changer? I hope its not for dosing...that would be something to see...lol.


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## Wasserpest (Jun 12, 2003)

gmccreedy said:


> I have seen many people doing this, its nothing new and as long as the solution is dilluted and mixed properly, it has never caused issues that have been expressly stated.





indiboi said:


> Indeed, one just needs to make sure the solution is stable at the temperature it'll be stored. I goofed a little when I added the K2SO4 to my solution without adjusting the water volume, it's just a bit too close to the limit when at 75 degrees in my stand.





original kuhli said:


> Cool, thanks...the last thing I wanted to do was add a stirrer to my already silly bill for autochanging and dosing...





indiboi said:


> No problem. I like to keep my solutions extremely concentrated, as I believe it helps prevent weird things from growing, but care does need to be taken so as to not make them so concentrated they fall out of solution.  If you stay far enough away from the limit they will stay in solution indefinitely.
> 
> Hehe, I'd put a stirrer on the list anyway, I'm eventually going to get one. Every couple of months I go to ebay, put one in my "watch list" and then I don't buy it. I can imagine mixing things up to be so much easier, but it's hard to justify the $80 for something I can do myself by shaking the flask.


For macros, I recommend the Wasser-Pump method, which will mix the mixture each time the doser doses! :smile:


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## bgoodwins (May 3, 2007)

Shameless plug. Shameless i tell you!


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## AndrewH (Dec 24, 2007)

gmccreedy said:


> What are you planning on doing with those? A water changer? I hope its not for dosing...that would be something to see...lol.


Yeah, I have them on my water changer.

Dosing with a solenoid would be pretty tough, but probably do-able if you wanted to work out the math.


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## imeridian (Jan 19, 2007)

*Follow-up: Some Issues*

The check valves and tees have become clogged, partly because of flush timer failure allowing the Fourish and macro solution to mingle, and partly because some strange gelatinous substance has formed within the lines. The line with the Flourish in it actually blew off from the tee, splattering fairly well the inside of my cabinet.

I'm still having tremendous difficulty with my timers, they seem to constantly reset. I haven't forked over the cash for the Aqua Controller yet... a 42" LCD TV has taken control of my finances for the next while.

I've removed the check valves as of this writing, they seem to get in the way more than help. Without the check valves in the way I can pop the tubing off the pumps and do a back-flush periodically. 

I'm not really sure exactly how well this is going to work without the check valves though, they allowed for filling the line completely with solution and then it basically 'dripped' out from the valve and then was flushed into the system. Now they're open, but I figure the solution only has one place to go, which is into the aquarium, so even if it isn't as even as before I suppose it's okay. I guess I just don't like being unable to squeeze the air out as I did before.

I still don't really know what the "best" way to go about this would be, but I can say that the 'multiple lines into one' certainly isn't it, at least not in my original design. 

I think I'm going to purchase some manual timers and just adjust my solutions to work in fifteen minute increments.


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## Wasserpest (Jun 12, 2003)

Not sure about your timers. If it is just the Grasslin type that acts up buy some other brands. They cost under $10 in Target etc. and allow for minute precision.

I find it advantageous to inject fertilizers back-pressure-less, just open ended lines over the rim into the tank. That way you don't have to deal with clogging check valves and back pressure which might fill your fertilizer bottles with tank water. :icon_eek: 

I use peristaltic pumps for micros (Flourish) in a concentrated solution, and there are few clogging problems. For macros, I use a little water pump as I mentioned earlier, which is extremely reliable, and as a side benefits, agitates and mixes the solution each time during dosing.

I have the 6x irrigation timer/relay setup ready to assemble under my desk, but haven't had a quiet hour or two to sit there and solder it all together. I'll share the results once I have them.


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## imeridian (Jan 19, 2007)

Yeah, I think I might just go with the over the rim method. I really liked the idea of injecting in-line, but it seems really prone to problems, the sort that show up unexpectedly. 

I haven't been able to find any decent digital timer locally, especially not for less than $10.


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## Wasserpest (Jun 12, 2003)

Target, Walmart, Kmart, Home Depot, Lowes... maybe not decent, but you should find something that doesn't randomly reset.


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## imeridian (Jan 19, 2007)

Contrary to popular belief, I actually know how to go to stores and look at items available for sale...  

It turns out that I had just enough tubing to set the peristaltic pump outflows over the edge of the tank. So, for now anyway, I'll just be dripping the solutions into the tank as you've mentioned doing.


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## Bodo (Apr 19, 2008)

How often do you change your tubing in the pumps? I know that in teh lab we have to change our tubes at a precribed interval to ensure accurate pumping. We also see degraded pumping when the tubing is left clamped in the pump. 

What are your experiences?

Thanks


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## imeridian (Jan 19, 2007)

I haven't changed the tubing, it's norprene and considering the pumps are used for less than 20 minutes a day I figure I have a considerable period of time before I need to even concern myself with it. I have several feet of the tubing on hand should it become an issue. Considering I use EI dosing, some error is fine anyway. It's a valid point, but at 3rpm there isn't exactly a lot of wear and tear either.


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## imeridian (Jan 19, 2007)

In April I posted an update that my inline dosing wasn't working as hoped, that the check valves were clogging. I then switched to simply dripping the solution into the tank from above. 

I have recently found that the tubing for the micro nutrients was clogging due to air exposure at the ends. Not just at the tip, but throughout the line. I expected the tip to clog and would routinely clear it out with a toothpick, but I didn't expect it to clog further back. 

I also discovered that the last bit of Flourish in the 2L jug had turned to sludge, further clogging up the tubing. Unfortunately I didn't notice sooner because it seemed to pour out of the jug fine (after being shaken). It just settled out over the week, leading the peristaltic pump to try and pump the sludge instead of the liquid. 

I went through and cleaned the tygon tubing that goes from the fertilizer reservoirs and replaced the silicone tubing I had been using to get the ferts up to the dosing point. I'll be replacing the tubing on a more regular basis now. Since I swapped the tubing I figured I'd try a different nozzle. The old makeshift ones were rather short and would cause the solutions to creep. I wound up with a mess of crustiness. I hope this will work better.










It's just a piece of acrylic tubing that I had already with the silicone tubing fed through and capped with one of those disposable airstone connectors.

I've taken to using a single $5 analog timer from Target. It has been more reliable than the fancy Grasslin timer would ever dream of being. I use a single timer and one of those outlet adapters (the sort that is three plugs into one) and just dose both solutions at the same time. The rates are slightly altered, with a little less macro and a little more micro, but it's been fine. 

They were dripping into the water at the same time from the same location and that was also fine, none of the dreaded precipitation effects so many are quick to warn about. The location of the nozzles allows for the nutrient to be quickly dispersed, as it drops into the filter outflow. I have though, as you may be able to figure from the nozzle photo, separated the lines to different sides of the tank this time. This is more for mounting convenience than anything else, but given some recent experiments I'm a little more concerned about possible interactions too. They'll still drip at the same time and for the same duration though. 

I'm considering revisiting inline dosing, but with the brass CO2 grade check valves and a separate port for each solution. It just means making another reactor or having a separate dosing manifold. The separate dosing manifold, connected inline like a heater, seems a bit better to me, but having yet another item inline seems like a bad idea, so the new CO2 reactor with extra ports may indeed be the solution. If I do that I'll likely go back to the dual timer setup I originally had, just with the analog timers.


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## Gatekeeper (Feb 20, 2007)

Keep in mind that if you run it inline in a manifold, that you need to put alot of shut offs in to be able to isolate the feed ports for maintenance, especially if you are now a tube change regiment. Otherwise, you will have to drain the entire line to do any work.

I have made this mistake before... it is not fun to try and undo what is already built.


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## imeridian (Jan 19, 2007)

I had used the check valves to keep water from exiting the port previously, turning off the flow and allowing it to drain down to the port was fine back then if I had to remove the checkvalve. I don't really see the need for shutoff valves, since I don't use them for the UVS, CO2 reactor, or heater. Maybe I'm missing something? 

I'm in the mulling over phase. I had priced out building a new reactor or injection manifold back in April and decided not to bother. I'll probably keep with the current dripping method, it's easy. It seems no matter how it is done there's a drawback of some kind anyway.

The nagging little suspicion is that I'd still be clogging the check valve even though the macro and micro solutions would be separate. The fittings on the drip system were encrusted with Flourish, inside the tubing, so that puts leaving well enough alone in the winning position for now.


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## agutt (Oct 28, 2008)

I just finished my version of imeridian's Fertilizer Dosing System, and I wanted to share it with all of you. Basically I have the exact same system that imeridian has set up. I am using 2 SP100 Peri Pumps (.65mL/min) that I have mounted to a very simple wood frame. When I bought the pumps, I also purchased the exact same norprene tubing that the pumps so that I wouldn't have to step up/down the tubing sizes. I loved imeridian's idea of using H2O2 bottles for the ferts and got 2 500mL bottles from CVS for $0.99. The outflow of the pumps runst to the back of my tank and then attaches to a hook that I unscrewed from a wooden clothing hanger. I used cabel ties to attach both hoses. This allowed me to get the tubing over the edge of the tank enough for the ferts to drip in. I also wanna point out that I am using no check valves of any sort. Since there is no contact with the tank water they are not really needed. The Pressure from the Peri Pumps also sort of acts as a check valve just in case. 

The Macro pump goes on for 1/2 half hour every day at 12pm (before the lights come on at 1pm) everyday. The solution is measured out so that a half of a full fert dose gets pumped into the tank every day. 

The Micro pump goes on for 6 minutes every day at 12am everyday. This solution is also measured out so that a half dose is dosed every day.

I put them as far apart as possible so that there would not be any issues with the macro and micros missing. 

The macro solution should be good for 3 weeks, while the micro will be good for much longer...

I am using an aquacontroller jr. to control the whole tank. When I do my weekly water change I simply run the Peri Pumps for a 'full' dose of ferts to re-charge the tank.

So far everything is working smoothly. This is the first autodosing system I have ever tried, and I would highly recommend it!

Much thanks to imeridian!


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## imeridian (Jan 19, 2007)

Very nice! Thanks for posting your version.


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## Gatekeeper (Feb 20, 2007)

Very nice.


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## Gatekeeper (Feb 20, 2007)

How did you time the "Full dose"? Did you set it up as a FEED cycle on the controller?


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## agutt (Oct 28, 2008)

gmccreedy said:


> How did you time the "Full dose"? Did you set it up as a FEED cycle on the controller?


:thumbsup: exactly! I have one feed cycle for the Macros and one for the micros. I contemplated just doing it manually, but this is more buttons as well as the fact that I would probably forget that I had them on and overdose the tank lol...


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## DannyH (Dec 17, 2008)

Quick question, how did you mount the pumps? Got a profile pic? Im just trying to sort mine out . Cheers mate, I appreciate it.


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## imeridian (Jan 19, 2007)

I used little "L" shaped brackets from the hardware store, screwed into the stand and attached to the pumps with small machine screws and nuts. You can see most of that structure in the pump photo on page 1.


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