# DIY Automatic (liquid) doser



## f1ea (Jul 7, 2009)

Hi all,

I looked around the forum to find somehting i've been thinking of, but couldnt find anything related.
Im trying to figure out a way to do automatic dosing of liquid (or a prepared solution) ferts and/or Excel.

What i am thinking is very simple: something like an IV drip solution bottle placed higher than the tank; with an adjustable drip valve (like the ones used in hospitals) connected with a 1/4" airline hose releasing the solution in the tank somewhere in the vecinity of a powerhead/filter outlet.

I can calculate and make a solution for... a week for example... then adjust the valve to drip constantly at the desired rate. Using the MEAN drip flow to calibrate the valve (flow is largest when the solution bottle is full and lowest once its almost empty). The higher i place the bottle, the less deviation in flow i will have at the different levels.

This can be used for liquid ferts and/or excel; and specially useful during holidays and vacation. But first i want to try it while i am at home so i can monitor how it works.... i'm guessing i have to protect the bottle(s) from light.

Downside (so far!) is that i will be dosing constantly, even at night, and i will have an unsightly bottle as if my tank is on life support. But it could work, specially if i am going away for a weekend, or for a week........ who cares how my tank looks if i'm not there to see it? or maybe i can hide it well.

Another way to go is with automated/electronic dosifiers, but i have not found much related; with timers, pressured air lines and valves and such.... i dont know, sounds complicated and expensive already. 

Anyone has tried something like this??? does this idea seem like it could work?? what could go wrong??

Ideas and criticism welcome.......

Regards!


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## intermediate_noob (Oct 18, 2007)

Something like this?

http://www.marinedepot.com/dosing_pumps_top_off_kent_marine_aquadose-ap.html


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## ghengis (Jun 11, 2008)

Or this...?

http://www.aquaticplantcentral.com/forumapc/diy-aquarium-projects/59729-diy-liquid-auto-doser.html


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## f1ea (Jul 7, 2009)

intermediate_noob said:


> Something like this?
> 
> http://www.marinedepot.com/dosing_pumps_top_off_kent_marine_aquadose-ap.html


 This is pretty much it. It is gravity fed, but looks pretty DIY anyways... costs $50, so not much. But i can make the same for a LOT less.



> Or this...?
> http://www.aquaticplantcentral.com/f...uto-doser.html


This is more or less the complicated and expensive version of what i am thinking about. But WOW it's over $500 bucks!! This one uses pumps and electronic timers to bring the solution into the tank. The BIGGEST problem in this case is calibrating the flow for the pumps. You really can't use the nominal pump rating, and you need to adjust pumping times and have timers for each different solution (liquid)... It will fail if there is a power failure, so definitely not the best thing for 'vacation'. Could work, but needs some good tweaking.

Thanks for the replies!


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## DJKronik57 (Apr 17, 2006)

I've built a really simple DIY auto-dosing system. Total cost is about $30. Works like a charm and I only have to refill it every 30 days.

http://www.aquatic-eden.com/2009/01/creating-diy-fertilizer-auto-dosing.html


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