HI, I def wouldn't stick it on the back of the tank, I would place on one of the ends of the tank. You would have more than enough flow if placed on the end of the tank, but don't think it would be wide enough to work properly on the back wall of the tank.
Cheers , need pricing before I commit. How much did you pay btw? Also please give me a noise report. Lots of negative feedback out there...
I paid $390 each but I've heard if you shop around can get about $370. In pulse mode there is a slight humming at the higher %. But doesn't start becoming audible till about 40%. And certainly not a major problem ( although tunze's were silent). In reverse mode a lot noisier so we don't use it. You are able to direct the 2 paddles at any angle you want so shouldn't be a problem with your fine sand. Just direct it away from sand bed & go just above it. I only run mine at max. 50% on a 7 footer so I would suggest that 20% max would do the job in a 3 footer. Hope this helps
They haven't hit here yet either.
