peristaltic pump

I was given Rays homemade calcium reactor a while back and I made use of it by cutting it down, adding a recirculation pump, drilling a few holes in it and making it into a kalk reactor.

I have it set up through a relay that controls 2 aqualifters. When the pH is below 8.26 one pump pushes RODI water through the reactor, when the pH reaches 8.26 my aqua contorller tells the relay switches and it turns on the other aqualifter pump to bypass the reactor.

After running it for a few days one flaw that I realized is that the aqualifter is a bit under power and the pump doesn't prevent the water from siphoning back to the RODI container so kalk paste would end up in the RODI container. I added an anti siphon valve to the line that goes into the reactor but the aqualifter could not push water through the reactor.

When Cory start this thread I had the idea that I could use a peristaltic pump to push fluid through the reactor. so I ordered this peristaltic pump off of ebay and patiently waited for it to show up from hong kong.

I received the package yesterday and quickly went to work building a box for it so I can get this back into the tank.

So here are a few photos of the process











I added a 12v dc power supply to it and have it hooked up under the tank. So far it seems to be working well. I will have to monitor it for a few weeks to put my stamp of approval on it.

See, I knew youd find a use for that monster.

How loud is this DIY peristaltic pump? I'm looking to use something similar for an auto top off. I already had a similar peristaltic pump from ages ago but the gears were too loud when running. Nice build on the box by the way. I do a lot of ABS, PVC, and acrylic work...and I can tell you went the extra mile on this. I'm not really a big fan of all the sloppy (and frankly dangerous) frankenstein'ing that I see on forums...though I've had my fair share in the past.

Well thanks for the compliment. The only sound that I can hear from this pump if from the electric motor that’s spinning. It’s fairly quiet however definitely not silent. I have since removed my kalk reactor and have taken that pump offline. Maybe I can make a short video so you can hear the noise it makes.

How much does the unit slow down if you reduce voltage? For example, I plan to use a small, 6V mini-peristaltic pump as I only need 100-500 ml/h, which is fractional gallons per hour. I was planning use a DC voltage controller (from Ebay) or potentiometer to dial down the the voltage if need to get it to slow down.

Don't use just a potentiometer, you can use a PWM to control the power supplies output. Somewhere on this site I have a schematic for a simple PWN that can be controlled with a pot. What that does is instead of wasting the power and converting it to heat (through the resistors in the pot) you simply turn the voltage on and off quickly at varying rates to control voltage output.

The power supply that I used is from radio shack, the voltage output can be changed from 2.5V 3V to 12V. I’m pretty sure it just uses a linear voltage regulator to change the voltage output. But that’s an option as well.

Here's the link

http://www.masvc.org/t158-diy-stirrer

Agreed. I'll use a PWM to not waste energy to heat. Since I'm a bit short on time these days, I'll use a low power pre-fab one from Ebay. I've found 3 amp units (more than enough current) that retail for <$10 with shipping.

Thanks for the great link by the way. I built nearly the same thing - but without a PWM as it was more than a decade ago - using the inside of a 3 inch PVC pipe cap from Home Depot to store a 2" AMD CPU fan (cut the blades off). Anyway, it spun too fast...and there was not enough surface area on the 3" cap for anything bigger than a large pickle jar. This said - I may "infringe" on your idea a bit. Thanks!!!

No worries,

You can use this dimmer. It's a bit cheaper and has a higher amp rating (not necessary in this application though). People are using it for their WP25's and are having good success with it.
http://www.ebay.de/itm/Dimmer-LED-strip-Light-Adjustable-Brightness-Controller-DC-5V-24V-for-3528-5050-/160950878751?pt=US_Lighting_Parts_and_Accessories&hash=item25796b821f#ht_4337wt_1117


And here's the video as promised:

Great video - thx! I'm now 100% convinced that I should do a DIY 6-12VDC dosing pump utilizing a PWM motor controller. The 6VDC units are so small, I may do a dual version. I'll post a video of it...when I get around to it.