AquaticTechTank.net

This is a great find.

Peristaltic Liquid Pump with Silicone Tubing - ID: 1150
http://www.adafruit.com/products/1150


price: $24.95

You can use pwm to control the speed.

Controlling it with pmw with a diagram like this. Not sure if a capacitor is needed.
* Actually, the capacitor is necessary in case there's a short to protect the Arduino.

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DC Motor and Transistor.png [ 17.13 KiB | Viewed 18588 times ]


Basic instructions and parts list on controlling motors

https://learn.adafruit.com/adafruit-ard ... s/overview

Do you think something like this can be controlled accurately enough to automatically dose ferts? I would expect that it should be as simple as figuring out exactly how much it moves in some amount of time and then setting it up on a schedule. Maybe use a check valve or something to keep the liquid from flowing back down into the storage container while it's idle. Pretty cool that you never have to worry about gumming up an impeller or such.

A check valve should be redundant. The pump should have at least three points of contact with the tubing. So the tubing should always be pinched off at some point even when the pump is idle. Sort of like a revolving door always keeps the air out of a building when it isn't spinning.

Not saying a check valve is a bad idea. Just saying it isn't essential.

Has anyone tried this pump? I am using a Raspberry Pi to control the flow into a nitrate reactor, right now my control system is just turning a solenoid valve off and on based on ORP levels. But this sometimes causes big variations of the ORP in the reactor, so am looking at using a peristaltic pump instead. My questions:

1. how noisy or quiet is it when operating at low speeds? its going to be in the cabinet below the aquarium in my living room...
2. can it withstand a bit of pressure on the input without leaking? current input to the reactor is from a tee on the output of my canister filter. I guess i could switch it to pull water directly out of the aquarium, though...

thanks
Don

I'll be getting a few of these soon to try out. I'll let you know.

As for the pressure/leak question, I don't see it affecting the pump.
Why would the input have pressure? I'm assuming you're pumping in some nitrate eliminating enzyme.

Great, let me know how it sounds/works!

I'm not pumping enzymes into the tank, I'm controlling the flow of tank water into an Aquamedic Blue nitrate reactor. Its currently fed from a tee on the output of my canister filter, with a needle valve to control the flow rate and a solenoid valve to turn the flow on/off based on a control system running on my Raspberry Pi. I'd like to leave the plumbing as-is and just replace the solenoid with the peristaltic pump, since that way I'm running clean filtered water into the nitrate reactor...

regards
Don

I bought 2 of these. One for macro nutrients, one for micros but if I'm fancy enough, I'd do one for KNO3, one for KH2PO4, and one for micros.
Here it is running at full speed straight from a 12VDC adaptor (it's really 18V according to my voltmeter).



The high pitched buzz is the motor and the popping sound is air going through the tubes. It might not be as loud is if it was pushing liquids.

thanks very much for posting this - based on your video I think it probably is way too loud for my situation. I've also been looking at something called "Toms Aqualifter" which I understand is quiet and fairly cheap. doesn't seem like it is peristaltic but I'm only pumping water so it should be fine as long as the flow rate is reasonably constant.