40 times volume flow?

[gregzz4]

Besides it being mentioned that's too many fish for your tank

6.1x your total system volume is enough for flow through your sump for most skimmers to work correctly

The 35-40x flow is total/combined flow in your tank for the highest flow requirements of some SPS. This includes your return pump ( 6.1x sump flow ) + your intank stuff ( powerheads/closed loops/wave boxes )

You don't need such a high flow rate if you're not keeping only the most finicky SPS, and such a flow will probably destroy lots of LPS

Depending on what you plan on keeping, you can get away with much lower flow rates such as 20-25x total turnover

So, for your 55g tank as an example with a 15g sump ( total probably close to 60g ), your return pump would work well with 350-400gph
Your total system volume in my model is 60g, so 25x is 1500gph-400=1100
Divide that by 2 and you only need 2 powerheads of 5-600gph each

Of course, this is just a gestimate, and having multiple powerheads in a system is better than 2, in most cases ...