iwishtofish
Active member
No.
The K4's should provide enough movement in a 75. When I ran Koralias, I had a 2 and a 3 in a 58(same width/height, 3ft long) I had them on opposite sides, pointing towards each other and had a nice grye and random flow in the middle. I placed one up top and one about 1/2 down.
They have a decent broad flow that slows down the further out you get. Get your rock in there and watch how particles float around. If you have movement at the opposite end you'll probably be ok. The other option, and it may be too late for it, would be to have the return at the viewing end.
Ok, I guess I'll just have to do some tweaking once the rock is in. I have been reluctant to place any powerhead down at the "clean" end of the tank, but this may be unavoidable. I have a couple more smaller Koralias that I can deploy, if necessary. Thank you.