Wasserpests Microdoser

[Wasserpest]

While others polish their shiny cars or consume alcoholic beverages while watching NFL games, I am busy constructing my next auto-doser. Of course I could buy a bunch of peristaltic pumps and Liquidosers, but where is the fun in spending $1000 when you can do it yourself for <$100.

Here are my 5 stages of autodosing:

1) No dosing.
Disadvantage - plants didn't like it.

2) Manual dosing twice a week.
Disadvantage - gets old really quick, just like DIY CO2 on a 100gal tank.

3) Powerhead dosing.
Great for macro dosing. Disadvantage - micro solution starts to grow stuff in it.

4) The Fluidoser.
Works great for dosing ~2ml/day or more. Disadvantage - regular checkvalves
fail (leak) with smaller quantities, like 0.2ml/day.

So there it comes -

5) The Microdoser. This beauty will supply my 10 gal tank with concentrated solutions of micros and phosphates.

Here is what we need:



- a mechanical timer
- a toggle bolt (which is a fancy drywall anchor)
- 3 syringes
- a cap which sits on top of the bolt
- a container which contains the syringes
- some way of connecting the container with the timer



To assemble, we drill a hole into the cap, drill 3 holes into the bottom of the container, and drill a big hole into the container cap (so the timer wheel can still spin around). Drill another hole into the center of the timer wheel, I made it so the metal bolt could be screwed into it with some effort and is now permanently stuck there.
I used a Knorr Chicken bouillon plastic container which is semi-transparent, nice, that way light is kept away from the micro solution, and I can still see what's going on in there. This container needs to be tall enough to contain the syringes with their plunger pulled out. See your (or your mothers) kitchen.



Finally, all assembled, just need to add some hoses. I used 6 ml syringes, and each day, each spin of the timer wheel, each step of the drywall anchor thread, advances 0.2ml of Flourish, Flourish Iron, and Phosphate solution into my 10gal tank. So I and my plants are set for 5-6 weeks of dosing.

Credits for the initial idea go to Mr. Ruud from Holland: Prototype slangen doseerpompje voor een tientje.

[epicfish]

Haha, wow. Very creative. =) Kudos on the idea.

[filipnoy85]

wow... just saw this thread... amazing.

[glass-gardens.com]

Wasser, even if the original concept wasn't yours, you still deserve massive kudos for your engineering skills, that's about the most ingenious project I've seen on this forum.

You could adapt this design to different dosing rates by using different pitch threads or different size syringes.

I don't know what you're doing for a living, but if it doesn't have anything to do with design, you're talents are being wasted big time.

I sent you a PM.

[Wasserpest]

LOL, talk about rediscovery... Thanks T, now I know what you were talking about in your PM. I think I'll keep this a hobby though.

This is now running for a couple of weeks, and doing okay. One thing I noticed is that if the hoses are submerged in water, the tank water mixes with the micro solution which isn't intended. If I leave them hanging out of the water though, the solution moves so slowly that the drops turn to a black gooey stuff with the flourish, and salt in the case of phosphate.

Solution - I will add check valves to the end of the hoses, and leave them submerged. We'll see how that works.

[vidiots]

Originally Posted by Wasserpest

This is now running for a couple of weeks, and doing okay. One thing I noticed is that if the hoses are submerged in water, the tank water mixes with the micro solution which isn't intended. If I leave them hanging out of the water though, the solution moves so slowly that the drops turn to a black gooey stuff with the flourish, and salt in the case of phosphate.
Solution - I will add check valves to the end of the hoses, and leave them submerged. We'll see how that works.

I think you may run into problems with gunk building up on and clogging the check valves causing them to stick either open or closed over time. I'd be very curious to know if this becomes a problem.

[Wasserpest]

The checkvalves would be there to prevent backflow of tankwater into the solution while keeping the outflow submerged. Don't know if they would stick open or closed... if they stick closed, the whole setup would probably blow up and if they stick open tankwater would go up the line, which would be visible at least in the micro solution. I'll try and let you know in a few weeks.

[Aquamanx]

What did you do to "Bleed the line", Just crank the timer ahead? This looks pretty doable! Please let us know how it wokrs in another week or so, After you get the bugs out, I just may try this. I have SOOO many mechanical timers in a bin full of fish & lizard habitat extra parts, I wouldn't be worried about sacrificing one... LOL!

Thanks for the idea!

[Wasserpest]

To "bleed the line" I just sucked some solution into the syringe, then held the line up so I could get all of the air out of the syringe and airline, then filled up the syringe. I am using thinner airline, the capillary tension holds the liquid inside, it doesn't drip out of it all by itself.

Once the syringes are assembled, I rotate the drywall anchor until they are under slight pressure. Might take a day or two until they actually start dosing. When the whole thing is assembled, it is pretty impossible to turn the timer wheel.