GPH Question

[TheGuyWho]

I think I made another wrong move... I was told (by someone on here) that for my tank I should have somewhere in the ballpark of 3000 gph. I thought that seemed like alot, so I went ahead and just got (2) Koralia powerheads, circulation level 3 @ 850 gph each. These things flow crazy! Its too much flow. It blew one of my Xenias right off the rock it was perched on, and I think it killed it actually. I was trying to find a spot where I could let these things flow without blowing right on my corls, but its been very difficult. For now I just turned one off. But I think the damage has been done. The Xenia seems to be shriveling, and alot of the arms appear "bent". Thoughts guys/gals? Help?
I think Im going to return one or possibly both of the 850 gph powerheads and knock it way down to the circulation 1 level of only 400 gph...??? Im not planning on having any hard corals really, so I just don't think I need that much flow in my tank. Its a 100 gallon tank, but I have A LOT of rock.

[rgrobe]

Wow, I've always heard 3x-6x turnover rate for a reef tank. That seems to be the rule of thumb. In your case that would amount to 300-600 gph, not 3000.

I have a 180 and run two Korallia 4s and one Korallia 3 and get good flow without being overpowering. I would think you could go with two Korallia 2s with no problems.

[Playa-1]

Thoughts guys/gals? Help?
30x your DT volume or 3000 gph in total circulation is a good starting point if your planning to keep LPS and Softies as you initially indicated. It should not be too much flow for your tank, but you will have to tweak the powerheads so that certain corals like the Xenia do not receive too much direct flow. Getting the Powerheads adjusted properly can be a little tricky. I'm currently running two K4 powerheads at 1200gph each and a return pump around 600gph for a total of 3000gph in a 90gal DT. I'm keeping LPS and Softies in the tank.

I think Im going to return one or possibly both of the 850 gph powerheads and knock it way down to the circulation 1 level of only 400 gph...???
Circulation is very important in your tank and 400 gph isn't going to cut it. If you've decided not to keep LPS after all then you might consider dropping down to roughly 20x your DT volume from all sources or 2000gph.

Are you running a sump or Refugium in addition to your Display tank or is your only source of flow from those two powerheads?

[Michael]

<a href=showthread.php?s=&postid=14345508#post14345508 target=_blank>Originally posted</a> by rgrobe
Wow, I've always heard 3x-6x turnover rate for a reef tank. That seems to be the rule of thumb. In your case that would amount to 300-600 gph, not 3000.

I have a 180 and run two Korallia 4s and one Korallia 3 and get good flow without being overpowering. I would think you could go with two Korallia 2s with no problems.

my tank runs at 35 times in flow, i have several soft corals as well and all is fine rgrobe, 3-6 times is fine through the sump but no-where near enough for a reef

[Playa-1]

What are the measurements of the tank?
Is it a standard size 100gal?

[TheGuyWho]

Its a 100 gallon corner tank, diamond front... With all 130 pounds of live rock in it and the 120 pounds of live sand Im guessing its around 85 gallons inside the tank itself. I do have a sump also, 20-25 gallons I believe. My plan is to grow mostly soft corals. Leathers, Xenia's, Zoa's, etc... I haven't decided on any hard corals because I really haven't found any that I like yet. Its a reef/fish tank, and not just coral...
Im thinking that if I keep these 850 gph's ill move them to the back, and then put two of the 400 gph's in the front so I don't blow things over.

[Ranchhand02]

Placement is key on powerheads. I have two koralia 3's in my 75 gallon tank and I have the same problem at first. I adjusted them until I could get the flow without blasting the corals.