Hmm, since this looks like a great place for advice building the proper flow - how many powerheads should I have for a 90g?
I adopted a tank, and currently have the returns split in two coming out at the middle pointing in opposite directions. These are driven by a Mag 9 (? - previous owner is unsure of exact brand). I also have a powerhead of some sort - also completely unknown.
Needless to say, I would like to improve on this situation and really know what I have. So... what powerheads should I be looking to get here? A Koralia 1400 and 2x 550s? Or would you recommend more / less?