Wasserpests Fluidoser

[Brilliant]

Originally Posted by RobChuck

I don't remember the exact quote, but this line reminds me of the Flowbee bit from Wayne's World.

Now that I look back and read it I am tempted to reword it.
I actually had that scene from Spaceballs in my head after reading it again, let me know if I should change my language.

This idea is awesome...its got my gears spinning...no pun intended.

[Wasserpest]

Nah, I think you got the message across just fine.

[exmt]

practically solving your part wear problem.

Any mechanical device will eventually will wear out..I'm just saying that in the other design there are less components to wear or fail.

The link above says this model doses about 0.75mL per 24 hr period, just enough for micros.

I apologize if the above statement caused confusion. I meant to say "enough for my tank"

Wasserpest, I'm not trying to ruin your thread. But I'm sure there's always another way to do things in DIY.

Regards,
Tony

[Wasserpest]

Sorry, I didn't mean to criticize you. Just thinking out loud. Comparing one thing with another. Your posts are always appreciated! And don't hesitate to tell me I am full of it if you think so.

[Wasserpest]

Weird thing is happening...

Mechanically it is working great. I connected some tubing, stuffed one end in a Flourish bottle (filled with water) and the other end in a measuring cup.

The plunger moves to push a little over 1 ml per rev into the cup. I can duplicate that by moving the timer wheel manually. Great.

Now I let it run on its own, and it manages to push around 3-4 ml of liquid per rotation. I am stumped... I could imagine with the slow movement it would push LESS, but about 3x the amount is weird.

Any theories why that would happen?

[Brilliant]

Is it possible its dribbling a little bit?
When you turn the gear manually it may be hard to recreate this but what I am thinking may be this...

the gear progresses forward but then settles back a little because of the torque the application is putting against it. So every click ahead (exhale) is also sort of a inhale as well as it rests against the gear locking it in place.

[Wasserpest]

Hmmm... good point there Brilliant. I understand what you mean, but with the syringe and plunger being plastic, it is a tiny bit flexible, and I would think there is no inhale action there. Basically the syringe is under fairly even pressure, even if the timer would actually click back a little, it would not releave any pressure from the plunger.

And I thought about leaking... but it should actually leak the other way around, resulting in less volume rather than more.

Any other ideas are welcome...

I will test drive some of the other units I made and see if they (mis)behave as well.

Another theory of mine is that it is leaking due to the syphon between the bottle (in), device and measuring cup (out). One would think the checkvalves would prevent that, but maybe not. To check, I can just turn off the unit and leave it be for a few days and see if any liquid makes its way into the measuring cup. Thinking about it, this could be a likely explanation...

[vidiots]

Could also be a delayed reaction that is skipped when you turn the dial quickly by hand. I would think that when you move it quickly your check valves open and close quickly, but at a slower speed the check valves have to first over come friction before the internal plug moves. Although like you I would have assumed it would pump less and not more.

[Wasserpest]

Yep, quite simple - there was a (very slow) siphon going from the bottle through the two check valves into the measuring cup. I raised the measuring cup above the bottle and bingo, one ml per rotation.

I need to let it run for a couple of days to see if it does now the opposite thing (siphoning back into the nutrient bottle). That would mean the check valves are not working for this sort of thing, and it would probably mean the end of this little experiment.

If it doses now consistently... well then I guess it's ready for practical application.

[Wasserpest]

Okeydokey, to bring this to its glorious conclusion...



I have two of them dosers working for two weeks now, no visible problems. I say visible because the whole deal is rather invisible. I measured a certain amount of liquid into the bottle, and put the date on it... So I know it should take 4 months to empty out, and I will check once in a while to make sure it does not empty out overnight or something like that.

Something to keep in mind is that not all checkvalves will work with this. (Anyone needs a good number of black plastic Tetra checkvalves?)

And, like I mentioned before, if you place the container above the tank level you might get a siphon going (not good).

Pretty sweet once it is set up and working... need to refill this late December, remind me if I forget.

[Wasserpest]

One thing I found to be a problem is if the dosing solution is placed underneath the tank, and a fairly long airline goes up to the tank, there is a slight head pushing down, and no micros are dosed into the tank since the checkvalves aren't that good.

To get around that, I integrated the micro dosing with the macro powerhead dosing as drawn here:



This way, the micros are injected into the macro hose at about the same level as the dosing bottle, and the amount equals whatever the syringe doses in one turn.

[SCMurphy]

Maybe you could make up a 'top off' doser like the Macro doser and not mix your micros with the macros. Just to avoid the possible Fe and P precipitate potential, while gaining the added benifit of 'topping off' the tank.

[Wasserpest]

Two reasons why I went away from the "top off doser" -- first, the mixed solution would grow "stuff" over time, and therefore second, needed to replaced and cleaned often.

Dosing full strength extends the maintenance interval quite a bit.

[SCMurphy]

What I meant was use a duplicate of your macro doser but just pump water with the micro's being added to the line. That way you wouldn't be mixing the macros and micros in the line which can cause problems of it's own. The reservoir would not contain a mix that would grow stuff and you would still be dosing full strength.

[Betowess]

Originally Posted by Wasserpest

Brilliant explanation, and thanks for pitching in! I guess it isn't that obvious how it works. Yes, the "In" side of the not-shown vinyl tubing will go into a bottle of Flourish for hopefully many months of automatic blowing and sucking, uhm, dosing.

This thread is cracking me up! Wow, this is too ingenious. I just started laughing out loud when I saw the first picture. I thought you were joking at first. Are you still using this successfully? . Any new modifications? PS, you could consider getting a patent design on this. I wonder if this could be mass marketed. Lots of aquariums around???

1. Does the syringe kind of twist in the timer? It must...
2. Do those clear plastic checkvalves work OK. What brand are they? (Not the black tetras obviously!)
3. And you're only using this Liquid doser for the traces/iron? What, with straight Flourish or have you tried any CSM+B?
4 Only dosing 2 ml /day six days a week on a 100 gallon? Hmm, maybe I'm overdosing.