Max pump I can use to increase water movement

You could add a couple more 750's in and that should help a lot. If you have a 4 bulb T5HO for lights then you could easily keep the SPS. The added flow from the additional Koralias would keep the SPS happy also.

 

its a 6-lamp T-5 HO made by aquatic life 4- 10k and 2 actinics

 

You are set for SPS with that. Just change out the bulbs to ATI, UVL, KZ or Geisemann brand bulbs. I would do 3 ATI Blue Plus, 1 ATI Purple Plus and 2 ATI Aquablue Specials. The Aquablues are white bulbs and the purple plus has some red to make your purple, pink and red colors stand out. The Blue Plus have a lot of actinic in them along with the other bulbs I recommended.

 

alright i will have to look at all that, how long do you keep your lights on?? mines on a timer, thats built in but im not sure how long i should keep them all on, my main lights are all on at 12, then my 10k's turn off at 6, actinics still on till 8, then moonlights on all night till 5 then they shut off completely till 8 again? should i give them darkness??

 

do you use 10k or anything like that at all?? i just ordered the ATI bulbs you recommended!! so we will see in a few days once it gets here, but im just curious about using 10k, i was under the assumption that you need to have some normal light along with the blue's

 

Ya... 4 lines is not the issue... return pumps should be sized for how much flow needed to supply filters in the sump. How many lines the return is split to is not a big deal. However... 4 outlets will have lower back pressure on the pump and more flow.... but the velocity of that flow will be less and reach less into the tank.

You want powerheads in the tank to provide water movement in the tank. Detritus on the sand bed is certainly a good indication you have insufficient flow. Certainly for SPS.

How much flow is a pretty broad question. Generally anywhere from 10x-40x the tank volume. How much rock, what your problem spots are, what inhabitants you have all contribute to what is the right flow for YOUR TANK.

So basically you are looking at powerheads that can give you 600-2300 gph and whether you need 1 or 4 is up to you.