Too Much Flow??

[saltywaters]

Is it possible to have too powerful of Powerheads? We have a 90 gal tank with 2 bulky M1500 Seio powerheads (see pic below). They are moving the top layer of sand and the fish seem to be having a hard time maneuvering around in the tank due to the high current. I may be wrong, but I can't figure out what to do with them. The power heads are both on the lowest setting, but I still can't help thinking there is just too much movement in the tank.
We're new to the hobby and bought a used tank that we transferred to our house and kept all the existing fish (except one that wasn't reef safe). Everything is great. The fish are doing very well, and we didn't lose anything during the move (thank goodness since we had a plumbing issue that drained about 7 gallons of water onto my carpet!!!!!)
Any help would be great!

 

[stanlalee]

you should be able to deflect the flow from 1500gph x2 in a 90g off liverock/glass to prevent sand blowing. its not too much for "normal" reef inhibitants (read unless you are keeping seahorses or something else that specifically require more relaxed flow its not too much).

 

[flower]

Your fish and coral will grow strong fighting the current, it is nature’s way for them to build strength. I agree with Stanlalee, you can defect the flow a bit if you need to by not directing the power heads at the glass. Try putting them on the side of the tank instead of the back, that way the flow must travel further before it hits the wall and bounces back.

 

[cranberry]

It won't make all fish and coral stronger... just those that belong/come from a high flow area. Anything that likes low to medium flow will not so well with high.

 

[flower]

Originally Posted by Cranberry
http:///forum/post/3200782
It won't make all fish and coral stronger... just those that belong/come from a high flow area. Anything that likes low to medium flow will not so well with high.

You’re so smart. I really mean that, I am not being sarcastic.
Now I have a question. Even if you have really crazy current there is going to be areas that are not as heavy in current. There would be a main stream and then the weaker spots. I always figured the fish and critters that like the weaker current just hang out in that area.
I am not talking about sea horses or Jellyfish, that need like almost no current, just regular fish that swim around.
Am I correct about the fish seeking lower current if they need it, or do I misunderstand how the water works in the tank?

 

[spanko]

Boune the flow off of the walls, if a pump is on one end of the tank place it about mid way up the glass in the back corner and point it a little up towards the other front corner. Do the same with the other one only on the other side. that way you have the flow meeting in the center and being "randomized" by meeting there. You will also get some good surface agitation which is needed for gas exchange. You really want to get to some random flow instead of just the linear flow.

 

[stanlalee]

Originally Posted by Cranberry
http:///forum/post/3200782
It won't make all fish and coral stronger... just those that belong/come from a high flow area. Anything that likes low to medium flow will not so well with high.
but I dont believe there's enough flow in this particular case to limit real estate to only high flow areas. My two powerheads provide way more turnover than that (x33 vs x79 or 1500gph x2/90g vs 1190gph x2/30g) and I still manage to have calm areas and areas with low enough flow for blasto's which hate flow, acans, clam ect without blowing any around.

 

[bang guy]

Grow some Seriatopora in direct line of the waterflow. They grow fast and will break up the waterflow very efficiently. I also think they look nice.