Water Flow

[psycho-killer]

hey all, im running a 1m lengt 38g tank, i have a 900L/h power head and a pump 1000l/h that i mounted on the side of the tank for more flow, at this moment i have flow from each side of the tank to the middle of the tank ? where should i point my flow ? both of them down the lengt of the tank ? or from corner to corner ? or just one powerhead running behind the rocks down the leng of the tank ?

 

[gigmeyer]

If my math is correct, you have about 13x flow with 1900l powerheads in a 38g tank. Since 20-30x is recommended for a reef tank, you'll need additional or larger powerheads to create enough movement in the tank. That being said, I believe optimal positioning is as much trial and error and will vary based on the location of your LR. The key is to avoid dead spots in the tank. Given the length of the tank, positioning the powerheads at either end and at different heights seems to make sense to start with. You may even want to try to create a circular flow around the LR. If you add additional power heads, consider a hyor flo or some other director to disrupt the flows and create a wave type effect.

 

[SkiFletch]

That being said, I believe optimal positioning is as much trial and error and will vary based on the location of your LR. The key is to avoid dead spots in the tank.

Yeah, alas there's no definitive answers here. Gig offers some great ideas so I'd try those. I'd also invest in another powerhead. Preferrably a stream type (Hydor Koralia, Tunze Stream/Nanostream, or Seio Superflow)

 

[Musho3210]

but is it going to be for a reef tank?

 

[psycho-killer]

its gona be a fowlr at the beggining when upgrading my lighs ill go full reef..

they are postioned at each end of the tank facing each other the one higher than the other one.

im getting an external canister filter with 450L flow,that will add also to the tanks flow, just scared im going to strong for fish or soft coral and crabs..

 

[gigmeyer]

ok, I'd say just add your canister into the flow to try and prevent dead spots anyway. At 16x flow it's hard to blow the fishes, crabs, or corals around. I think I'm at 25x flow now and fish have no problems at all except they occasionally take a joy ride at the powerhead outlet.

 

[Musho3210]

30x turnover for me, a bit too much for my meaty lps corals but i position the powerhead to not be as strong. 12-16x turnover is very little and you would be surprised at how weak that is compared to the ocean.

 

[SkiFletch]

you would be surprised at how weak that is compared to the ocean.

Anyone who'se ever been diving on a day with even moderate surge will say amen to that