# Overview of Autodosing Methods



## Wasserpest

Over the past years, several people have introduced autodosing methods and more or less successfully used them. For future reference, here is an overview of these solutions, along with some personal opinions with regards to cost and advantages/disadvantages of each method. I will update this post as new ways are discovered, or edits become necessary (let me know if there are any errors or omissions). If you have questions about specific methods, please post them in the threads for that particular doser.











*1)	Autofeeder*

http://www.plantedtank.net/forums/9-equipment/25337-autodosing-cheap.html

$: About $40 for the Pentair Aquatics Lifeguard feeder

+ Simple setup. Dry mix keeps nutrients from degrading.

- Integration into hood (sump would be advantageous). Moist air will clump fertilizer, might not work reliably. Fertilizer powder getting into the feeder will destroy the mechanics over time.

*2)	Test tube*

http://www.plantedtank.net/forums/20-diy/38735-easier-macro-dosing.html

$: Minimal

+ Extremely cheap. Very simple setup and fairly reliable dosing.

- Needs area of consistent high flow, like inside a filter compartment. Over time, biofilm can grow, or detritus can fall into the tube, reducing the amount of dosed fertilizer.

*3)	Syringe 1*

http://www.plantedtank.net/forums/20-diy/36845-wasserpests-microdoser.html

$: About $5 for mechanical timer, oral syringe and some small parts.

+ Good for very small doses

- Somewhat complex to build. Plastic syringes don’t last long. Dosing adjustment not very flexible. Needs strong timer motor.

*4)	Syringe 2*

http://www.plantedtank.net/forums/20-diy/34001-wasserpests-fluidoser.html

$: About $10 for mechanical timer, syringe, checkvalves and some small parts

+ Easy to adjust in a small range. Minimal maintenance once it is working.

- Plastic syringes have limited lifespan. Depending on checkvalves, there could be some back-syphoning if the bottle is underneath the tank. Somewhat complex to build.

*5)	Airpump 1*

http://www.plantedtank.net/forums/20-diy/27541-cheap-diy-liquid-doser.html

$: About $20 for an airpump, some tubing, and an electronic timer, $2 more if using checkvalves.

+ Very simple setup. Minimal maintenance once it is working. Very easy to adjust dosing over a fairly wide range.

- Difficult to get the needle holes to be the right size. Liquid (bubbles) remaining in the tubing might prevent refilling of the coil. Small changes in dosing depending on fillstand of solution.

(Here is a modified version of this!)

*6)	Airpump 2*

http://www.plantedtank.net/forums/diy/18086-poor-mans-auto-dosing.html
http://www.plantedtank.net/forums/diy/22116-poor-mans-auto-dosing-take-iii.html

$: About $22 for airpump, some tubing, checkvalves and an electronic timer.

+ Reliable dosing once the rate is adjusted.

- Mixed solutions might degrade over time. Changes in dosed volume depending on fill volume of bottles. 

*7)	Aqualifter*

http://www.plantedtank.net/forums/9-equipment/19319-cheap-dosing-pump.html

$: About $12 for the pump.

+ Simple and inexpensive setup.

- The Aqualifters output is greatly affected by head pressure.

*8)	Peristaltic pumps*

http://www.plantedtank.net/forums/20-diy/11564-diy-automated-dosing-topoff.html

$: About $80 for one pump and an electronic timer

+ Reliable dosing, easy setup.

- Cost!

Here is a link to an excellent DIY peristaltic pump!

*9)	Gravity fed*

http://www.plantedtank.net/forums/equipment/15017-kent-gravity-dosers.html

$: About $25 for the Kent unit and some tubing, ?? for an IV bag from your hospital.

+ Simple setup

- Difficult to place, unless a sump is used. Settling and degradation of solutions might occur.
*
10) Water Pump*

http://www.plantedtank.net/forums/20-diy/31643-autodosing-dummies.html

$: About $22 for a water pump, an electronic timer and some tubing.

+ Simple setup. Very reliable dosing. Minimal maintenance. Good adjustability.

- Solutions might degrade over time.


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## dipan

Really nice summary!


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## plantbrain

Great job thar!

Regards, 
Tom Barr


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## original kuhli

I have an additional ideas that I've yet to test... 

The central theme is using the constant outlet pressure of the CO2 system and a solenoid to pressurize a fertilizer bin and deliver a set volume of fluid to the tank/closed plumbing system. The costs would include solenoids for each of the two fert bins, the bins themself and checkvalves for each. This is the system I'd like to use on my tank buildup but I've not had time to test it. 

Also, the failure of my solenoid open has made me rethink this...


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## spypet

*sigh*
shame my dry autodosing idea didn't make the cut.
as I spent so much time coming up with it  

http://www.plantedtank.net/forums/equipment/38845-auto-dry-fert-dispensing-solution-here.html


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## Naja002

Good Job, Wasserpest! I see You've realized the short lifespan/value of the plastic syringes. I learned that with reptiles yrs ago, but always thought it was probably the soaking in alcohol that degraded them.

Did You ever get #2 (Test Tube) sorted out or are You still working on it?

I just bought 2 peristaltic pumps--which I think I will really like, but they are cost prohibitive for MTS! I think the Air-pump, water-pump and Aqualifter are probably the best systems--for the money! They offer *A Lot* of Bank-for-Buck roud: 

On the Water pump system--I say: skip the "powerhead" and get a small pump like a Via Aqua or Rio. My little Via Aqua 480 will pump about 59" head (straight-up) through 3/8"ID tubing---for only~$10-12. Reducing/controlling the flow isn't too hard.



spypet said:


> *sigh*
> shame my dry autodosing idea didn't make the cut.
> as I spent so much time coming up with it
> 
> http://www.plantedtank.net/forums/equipment/38845-auto-dry-fert-dispensing-solution-here.html



Hi Spypet,

I didn't even see that post until just now. Basically for dry dosing I think the Lifegaurd Auto-feeder beats anything else hands down. IMO, A lot of the things You listed either just won't work; or are way too expensive, put up too many stumbling blocks or both. Great Effort-Yes! But I don't think people that want to auto-dose really care whether its dry or wet. So, expensive dry solutions are pretty much out when we can have so much control via peristaltic pumps (x2) for under $200. With familiarity the air, water and aqualifter systems can be very reliable and offer Good control for --$25. Its Good to see that You are thinking outside the box--but its a tough challenge! roud:


Either way, I've seen most of these develop during the couple of yrs that I've been around here---so who knows what we will see in a couple more yrs!


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## Betowess

Nice summary. Maybe a little low on price on water pump method. 
The AS 606 is $16.49 before shipping from BigAls and a digital timer around $10.00 though I suppose one might find a better deal. Add in some hose and a flow control and your looking closer to $30 plus, IME. I spent ~ $13 each (shipping included) for a great flow control pincher from US Plastics, though I could have bought a much cheaper unit. That said, its all worth every penny since one's time should be considered valuble.

To anyone sitting on the fence, if you start autodosing, ya won't regret it! roud:


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## KDahlin

It's never come up on my radar before. Seems like a great idea as I'm not that reliable for manual dosing.


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## Wasserpest

original kuhli said:


> I have an additional ideas that I've yet to test...
> 
> The central theme is using the constant outlet pressure of the CO2 system and a solenoid to pressurize a fertilizer bin and deliver a set volume of fluid to the tank/closed plumbing system. The costs would include solenoids for each of the two fert bins, the bins themself and checkvalves for each. This is the system I'd like to use on my tank buildup but I've not had time to test it.
> 
> Also, the failure of my solenoid open has made me rethink this...


I think that approach falls under the Airpump 2 category. Problem with this concept is the cost... You can get a dual outlet airpump for $10, while two solenoids and two needle valves will be quite costly.


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## Wasserpest

Naja002 said:


> Good Job, Wasserpest! I see You've realized the short lifespan/value of the plastic syringes. I learned that with reptiles yrs ago, but always thought it was probably the soaking in alcohol that degraded them.


Thanks Naja  The alcohol will probably do them in that much quicker. The problem I came across is that the plastic plungers start to warp and finally give in. Oh well, what do you expect for $0.30...



Naja002 said:


> Did You ever get #2 (Test Tube) sorted out or are You still working on it?


Yes, that is working for several months now, and by far the most trouble-free system you can imagine. I have 3 test tubes (NPK) sitting in my AC Mini, I can even see the fertilizer level from outside through the translucent filter housing. I am now so confident with the dosing that I just fill up the tubes, the hole size in the stopper determines how fast they dissolve.



Naja002 said:


> I just bought 2 peristaltic pumps--which I think I will really like, but they are cost prohibitive for MTS!


Lol, I just _received_ two of their peristaltic pumps. It would be nice if someone would figure out how to DIY them using a mech timer. Maybe one of my next projects. All you really need is a round housing and some sort of roller thingy that fits inside there.


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## Wasserpest

Betowess said:


> Nice summary. Maybe a little low on price on water pump method.
> The AS 606 is $16.49 before shipping from BigAls and a digital timer around $10.00 though I suppose one might find a better deal. Add in some hose and a flow control and your looking closer to $30 plus, IME. I spent ~ $13 each (shipping included) for a great flow control pincher from US Plastics, though I could have bought a much cheaper unit. That said, its all worth every penny since one's time should be considered valuble.


You could be correct, I used to buy them for about $12, but they have probably gone up since. Like Naja mentioned, you can buy any cheap Rio or such. Digital timers, last time I checked they sold them in Target for $8, maybe it was a sale... I never saw the need for industrial flow regulation, I just used one of those drip irrigation connectors, closed one side off with a heated knife, then punctured it with a needle until the right size hole is achieved. Or use mini air tubing connectors. In any case, you can probably find something in your spare parts box. :icon_bigg


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## plantbrain

My issue is that I have to fiddle with stuff over the long term too much for it to be worth the trade off to get precise, accurate metering without going very $$$. While some methods work well on small tanks, they are not useful for larger tanks, thus scale is an issue.

I also have adversion to too much over engineering.
Some things are no brainers, automatic water changers etc, but I even avoid that going semi auto.

I feed my fish, some use auto feeders, but most do not, I suspect most of you do not as well?

May as well dose the ferts that way too. Takes a sec only, and you are there to feed the fish already.

Regards, 
Tom Barr


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## Wasserpest

I know what you mean... If you feed your fish daily adding some (perhaps pre-measured) ferts at the same time isn't a big issue. I used to do that, and hated it... :icon_bigg

The goal is to find something that you *don't* have to fiddle with. The water pump dosing is a very good example - cheap and easy to set up, and minimal maintenance on the long run. Every 4 weeks I refill the container, that's it. Running the pump for one minute a day does not wear it out, uses close to no energy, mixes up the solution, and is very reliable. I just can't see much reason *not* to do that, even for larger tanks.

I might be a little extreme, but I am having fun fiddling now to go near maintenance free for the long term. Looking at 3 of my tanks, this is what I am using:

*100gal:* (10) Water Pump for N+K, (4) Syringe 2 for Micros, manual for P. Will be using (8) Peristaltic Pump for Micros, and (2) Test Tubes for P.

*36gal:* (10) Water Pump for N+K, (4) Syringe 2 for Micros, manual for P. Will be using (5) Airpump 1 for micros and (2) Test Tubes for P.

*10gal:* (2) Test Tubes for NPK, (8) Peristaltic Pump for Micros.

This setup is/will be reliable, and I only have to spend maybe 1/2 hour every 4 weeks to check fillstands and replace mixed solutions.


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## Betowess

I'm with you 100% on the reasoning, and use your waterpump design with slight modifications. My only difference, and I haven't had a mold issue is, I put CSM + B and N & K in the main container. Manually dose P. 

In the future I might by a pair of peristaltics (one for each tank) and dose Trace that way and put NPK in the container/water pump.


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## unirdna

Incredible, altruistic effort! I cast my vote for a "sticky".


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## Wasserpest

Thank you Ted, your wish is my command! :smile: At least for a while so more folks have a chance to see it.

I received my peristaltic pumps and for some reason, they pump much less than I had figured. Probably my math that was off. :hihi: I guess I can run them for longer periods, no big issue, just another timer.


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## Naja002

Wasserpest said:


> I received my peristaltic pumps and for some reason, they pump much less than I had figured. Probably my math that was off. :hihi: I guess I can run them for longer periods, no big issue, just another timer.


What diameter tubing did You get with the pumps?


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## Wasserpest

I wanted one to dose about 0.2ml and another one for about 2ml per minute (for my 10 and 100gal tanks). 

Like I said, that day I must have been a bit math challenged and messed up calcs and order. I ordered one with 3rpm and 0.8mm tubing (~0.06ml/min), and one with 15 rpm and 1.6mm tubing (~0.6ml/min). I guess slower is better than too fast though.:icon_lol: 

After some testing I used the faster pump with the smaller tubing to dose the 10gal tank for 1 minute (0.25ml) and the slower pump with the larger tubing is dosing the 100gal tank for 10min (2ml). I guess in the end it worked out alright.

The slower pump is almost silent, the faster ones gears make a bit of a racket. I really like the small form factor, just tape a little fertilizer bottle to the pump, add some hosing, a timer, and off you go...


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## Naja002

Hey Wasserpest,

Did you have any problems connecting tubing to the tubing that came with the pumps? I got the 1.6mm tubing and looks like it comes with 1/16" hose barbs. I'm just wondering what You did for tubing from the ferts to the pump and from the pump to the tank......?

Also, You can adjust the dosage amount by diluting the solution more. In other words, my 120g setup would need 12ml/day under the PPS-PRO x 30days=360ml. A 20oz bottle holds roughly 591ml. So, 18mlx30days=540ml. 18ml divided by 1.5ml/min=12min cycle. This of course can be adjusted against actual output. That's my basic game plan at the moment.....:biggrin:


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## Wasserpest

I had some Norprene-like tubing from a friendly fellow member, as well as the usual air "Mini tubing". It fits alright, since there is no pressure involved it doesn't have to be extremely tight.

Diluting would be necessary if they pump too much, that's correct. I want to dose concentrated solutions, I think they don't degrade as fast as diluted ones.


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## Naja002

Thanx! I haven't received my pumps yet, but I did just pick up some medical grade 02 tubing, bubble counters, tank and a couple of regulators from a landlord that rents the place behind me--all Free. Now I just need a prescription to get the tanks filled. Anyway! the 02 tubing looks like a smaller diameter, so it may work. Don't really like the fact that its clear, but we'll see how it goes.

The solution can be diluted if it pumps too much or too little by adjusting the cycle time. In the end--its all about getting x-amount into the tank. Mine are estimated to run 1.5ml/min. At 0.25ml/min I think You've got a large margin of error! :biggrin:


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## scolley

Hey, great work WP! It's too late... but I still want to throw in a vote for sticky too! Really!

This is an outstanding starting point for someone considering autodosing. And for those of us that is has been successful for, that can make this hobby a whole lot easier.

Great job!


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## Betowess

Congrats on the sticky. I remember reading somethin Sergio said about getting the flow at the rated amount if the peristatic is set for full output. But if you opt for a variable flow unit, the ouput was not as consistent when setting the speeds. So the long and short, don't order a variable output, just use a timer or dilution to get one's desired ferts in the tank and use a one speed (flow) unit.


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## SuRje1976

Betowess said:


> Congrats on the sticky. I remember reading somethin Sergio said about getting the flow at the rated amount if the peristatic is set for full output. But if you opt for a variable flow unit, the ouput was not as consistent when setting the speeds. So the long and short, don't order a variable output, just use a timer or dilution to get one's desired ferts in the tank and use a one speed (flow) unit.


That's exactly right. I had a bit of an issue with getting repeatability with the variable flow pumps the further I deviated from full throttle. SO, I run them at full throttle and adjust the time they run for instead. Pretty simple to do with the timers I'm using (X10 macros), but if you are using a timer that is adjustable in increments of minutes, etc, you'd just need to adjust the concentrations of your stock solutions accordingly. There is, in my opinion, NO need to spend the extra $$$ on the variable flow pumps.

Great thread! roud:


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## Gatekeeper

SuRje1976 said:


> There is, in my opinion, NO need to spend the extra $$$ on the variable flow pumps.
> 
> Great thread! roud:


And this coming from a guy who is not afraid to spend $$$ on techy devices....

I almost fell over when I read this. Had to re-read this a few times for it to digest...lol.


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## lopez_316us

*Thank you!*

Wow! How I didn't see the before...

Really helpfull~~~!!!!

Thanks:thumbsup:


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## Wasserpest

You are welcome, thanks for the friendly bump. roud:

Last night I set up some auto test-tube fertilizing for my 135gal garage tank. Took two 6ml and one 3ml oral syringe (N & K and the smaller one for P), filled them with the powders, ziptie around them, and through a suction cup to stick them to the glass.

Just need to monitor a few weeks the rate in which the various powders dissolve. This must be the simplest way to automate fert dosing.


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## billb

Is there a good thread that discusses best ways to make stable solutions for autodosing? I have heard that people add HCl to the micronutrients to keep things from growing in the bottles and/or provide stability to the chelated iron? Is there any need to add a stabilizer to the NPK solution?


Thanks for your help

Bill


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## plantbrain

Excel works also in place of HCL.

Regards, 
Tom Barr


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## Wasserpest

Bill, there is a bit of discussion at the water pump thread.

I tried Excel, but didn't notice a difference. Possible that the concentration needed to be higher. Omitting KH2PO4 from the NPK mix really helped to prevent the smell that otherwise developed.


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## Chasintrades

http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+4430+4443&pcatid=4443

Has anyone had any success in utilizing this product for auto dosing of dry ferts?

In the product description it states...
Airline hookup will allow use under even the most humid conditions

Would love to know if this has been tried. For $29.99 to buy this, and the fact that I already have an air pump and tubing ($0 more investment) -I would be willing to guinea pig this. Just wondering if anyone has tried this product.


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## Wasserpest

Did you check out the link I pm'd you? That's where the Fishmate for Autodosing is discussed.

http://www.plantedtank.net/forums/equipment/25337-autodosing-cheap.html


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## Fishstein

*Anyone know best system for auto dry fert dosing?*

Saw the Fishmate thread - mentioned Lifeguard auto feeder. But that looks like it works with one large hopper - so how does it dose the same reliable amount of dry ferts every day?

What do you recommend?


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## Wasserpest

In that particular thread the OP mentioned that the Fishmate's bottomless compartments did not work for this purpose. It was replaced with the Pentair Lifegard.


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