Flow - Rule of Thumb?
 

Is there a rule of thumb when planning flow rates for a tank in relation to water volume?

For example the display section of my tank is ~22G. Return pump is 425gph with a single koralia 1.

But the return pipe has an attached Hydor water deflector so maybe it reduces flow by 20% to 340gph. That gives me 325 + 400 = 725 or 33X turnover.

I am having a detritus issue that I blame partly on my aquascaping and low flow. What range of flow is suggested for a softie/LPS tank and what range of flow is suggested for a LPS/SPS tank?

Can't answer your question other than to say, probably hard to get too much flow if it's right.

If you are having a detritus problem also need to consider flow to your filtration and the mechanical filtration itself. It's one thing to keep it in suspension but then you have to remove it.

I found that the more flow the better. My LPS would sway in my tank with a mag 18, koralia 2 and 3 aqua clear power heads i had in my tank (120g) and i added 2 koralia 4's and a koralia 3 to my system, and my LPS still sways about the same they just have to adjust to the amount of flow you put to them

I have what I would call a passive filtration. There are two overflows leading to the rear chambers. As the water leaves the display it passes over filter pads before either entering the either the skimmer or going directly into the refugium. Destination depends on which overflow the water goes through.

First step is to get the detritus is suspension. I may need to do more mods on the filtration.

OK, so here is my summary of your flow:
Mag 18 = 1,800 gph
Koralia 2 = 600
3 X Aqua clear = 3 X 400 = 1,200
2 X Koralia 4 = 2 X 1200 = 2,400
Koralia 3 = 850

=6,850gph / 120g = turnover of 57 X

Are the assumptions correct?

You probably have less than 120g of water so the utrnover would be higher.