Pump comparison

Just thought I would share the results of a flow test I ran recently. I was testing flow rates for pumps to use on my Algae Scrubbers, so far I've been using the Eheim Compact 1000 pump, which seemed to do pretty good, it pumped right on about 200GPH at 13" of vertical head (from top of water in tank to centerline of slot pipe). Since I was shooting for 210 GPH, I wanted to see if there was another pump that would provide just a little more flow. So I tested the Rio 6HF, Rio 1100, and the Cobalt MJ1200 (original Maxi-Jet1200).

I did this by measuring the flow out of the scrubber drain with a 1/2 gallon pitcher and timing how long it to to fill it, averaging the times and dividing in 1800. So the result is the actual flow rate in GPH. Here are the results:

Eheim Compact 1000: 200GPH

Rio 6HF: 197 GPH

Rio 1100: 229 GPH

Cobalt MJ1200: 191 GPH

What is interesting about this is that this flow point seems to match the flow head loss curve for the Rio and MJ pumps at about the 3' point, except for the Eheim, whose flow curve at 3' says it should be more like 120 GPH.

This tells me that as far as head loss goes, the Eheim pump has pretty good bang for the buck. The max flow of that pump is 265 GPH, while the Rio 6 HF is 350 @1' (no listing for 0') and the Rio 1100 is 380 (350 @ 1') and MJ is 295 @ 0'.

Those Germans sure make good pumps.

 

Haha

The above test was 5/8" ID hose into an elbow to a 3/4" pipe. The Eheim has a 5/8" outlet on it, so I had 'standardized' on that.

I got a burr up my behind and decided to test again using 3/4" hose into a 3/4" hose barb to 3/4" MIP 90 degree adapter.

The Rio pumps comes with several adapters and such to go to NPT and larger hoses, etc. So I figured I would try those also, and rig up the Eheim as well.

Eheim: 221 GPH (up from 200 GPH = 10% increase)
Rio 6HF: 271 GPH (from 197 GPH = 37% increase)
Rio 1100: 297 GPH (from 229 GPH = 29% increase)

However, I had to pop the suction cups off the bottom when testing the 6HF due to hose length, and oh boy is that pump loud when it's not secured down. No wonder it comes with those monster suction cups. It even comes with a secondary vibration isolator plate and another set of rubber separators.

I didn't pop the Rio 1100 off the bottom. I have an older one of these that I use for salt mixing and transfer and it stays pretty silent without the suction cups.

I had to hang the Eheim also - it remained dead silent.