for the 10 times flow is mainly for sps tanks and you can achieve that with a couple powerheads.. i almostmade this mistakewith the 180 i was going to bug a pump to double the pump o had now plus then i re read my old build smacked my head or being too stupid and now im planning either a ehiem 5000 or quiet one 6000

Flow through the sump has nothing to do with what type of corals are kept. As I said above, the purpose of the return pump is to feed the skimmer water to process. The skimmer can only process so much water, so increasing flow through the sump does no good. If you have a grossly over-sized skimmer then increasing the flow through the sump could possibly achieve a bit heavier skimming, but that would be negligible.

Powerheads are for provide flow for the corals and preventing detritus settling. For SPS corals you're looking in the 50-100x turnover range where LPS and softies are happy with 10-25x turnover.

I was using that very calculator, It is to bad it didn't have more pumps listed.

so i missed a zero at the end for sps :razz: i personally dont even have that much flow within the tank my new tank will have the option to turn on 2 more power heads if i choose but if he had 50 to 100 times in a 90 he must be careful of what substrate he adds to the tank.

Thanks for the input Mindy,
That will be next poll (Skimmer) :biggrin:
Looks like the 4000 will do the job based in RC calculator.

As for your second post, are you saying that for a 90 gallon SPS tank that a person should be looking for 4500 to 9000 GPH turnover ? If so looks like I need a couple of more powerheads.:wink:

Ehiem 1260 or 1262. Best submersible pumps you can get.

What are you using for powerheads ? Substrate ?
I will be using Crushed Coral and oolite sand on the 90. I have sugar size in my 36 with a couple of K4s and with my gobie digging around, I do get sandstorms.

i like the look of sugar sand and make use of sand sifting stars and an orange spot goby right now in teh 90 i have a koralia 3 and 2 plus the flow from return pump but i dont have alot of sps..yet.. but my new tank the 180 will have 2 koralia 1050s and 2 koralia 750's unlessi can find another used koralia 3 to match one i own already.

should i have more flow ..maybe .. but thats what future upgrades are for.. nothings perfect thefirst time

yeah what greg said, thse pumps are affordable powerful and controllable
what more could you ask for?

I opted for Not sugar sand. I found enough info that lead me to Not have sandstorms with powerheads
I bought this sand , or something very close to it