Safe Refugium Pump

[j0tca]

Hi Everyone,

I've been out of the hobby for the past 4 years or so and am excited about the changes in technology (LEDs, Biopellet reactors, etc). I'm just in the process of setting up a 220G SPS dominated reef in my living room with a tank room in the basement beneath it (I'll post a build thread once I get time with pics) One thing I'm hoping I can figure out is a safer pump to move water (and inhabitants) from a refugium to the DT. There's no way I can have an overflow from the fuge to the DT with the space and positioning I have. Has anyone run across or have any experience with pumps that aren't based on impellers? (as these kill the copepods etc). I heard rumors of a simple low flow piston style pump but never found it myself.

Thanks for any insight.

 

[r-balljunkie]

issh..Your choices are rotary lobe, multiplex plunger/piston, rotary vane, progressive cavity.

these are all positive displacement pumps...like dosing pumps...one revolution = x volume

A piston pump is a pump that’s on a "camshaft" of sorts, on the upstroke one piston pushes water, the other fills the cylinder, back and forth back and forth.

Progressive cavities use and elastomer on the outside, a screw on the shaft to squeeze fluid thru.

These pumps are relatively more expensive to run due to expendables, especially when compared to the simplicity of a centrifugal, not sure if anything is commercially available at a price point acceptable to the hobby.

 

[j0tca]

Disc Flo made a pump http://www.youtube.com/watch?v=a7D4TO2L6oE (This pump would work despite the lack of compassion towards the fish in the video)

However it was not tailored or applicable to our hobby. I'm surprised that no one has made a reliable cheap version of non centrifugal pump for us; the flow rate can be very low, even 10gph would likely be good I think.

 

[j0tca]

A little bit more research and I answered my own question. There doesn't seem to be anything targeted at us but I think I"m going to go with http://www.northerntool.com/shop/tools/product_200249074_200249074

After speaking to the representative they assure me that the interior parts are all stainless steal or their own plastics and it's is completely corrosion resistant to salt water (meaning the pump won't add anything bad to the water.) I'll be using this pump through a 1/2 bulkhead from a 40G refugium back up to the DT. The refugium will be fed through overflow from the sump. I'm not a big believer in high sump flow, so I'll have another return pump from the sump to the DT with reasonably low flow, about 800 gph. I'm going to aim for my return to be about 1.5 times the skimmer flow.

Whether the pump is truly safer for copepods remains to be seen. Unless I find a better option, I"m going to buy this. I"ll set up some test with store bought copepods and see how many make it through the pump alive after I get my system up and running. This will take me about 1 month to do.

If anyone knows anything better or has tried a different positive displacement pump, please share!