Flow - enough is never enough

[trspann1]

I had a slight issue with oxygen depletion (I believe) with a sudden fish death (all in one night, while all water quality tests were OK). I did notice a slight film on the surface, which makes me believe it may be oxygen depletion. Obviously the first thing to do is re-aim my power heads. The tank I am talking about here is a Red Sea Max for my daughter. It has two powerheads built in, but I can only run one at a time becuase if they both run, they sometimes overpower the amount of overflow going through all the filtration, chiller, etc. (I may cut the amount of pre-filter media down some more and just clean/replace more often). When I did this (go to only 1 pump) I added a Koralia inside the tank. My question is how I should set this up. It looks like others have said that having the powerheads on opposite ends is causing some film build up. I originally set it up this way because I thought (probably in error) that the two jet flows would cause more agitation when they meet. However, I have seen some say to put one near the bottom. So, should I continue to leave the two permanent mount powerheads pointing down towards all the live rock, and move the Koralie down low also and point in a similar direction, but upwards? Any help would be appreciated.

[Lotus]

I'd definitely point one more upwards to have some surface movement (which helps with oxygenation). It generally takes some trial and error with powerheads so that you have enough flow removing debris from the rock but not causing a sandstorm.

[TRe]

i dont think pointing a powerhead in the wrong direction would kill all yur fish in one night im thinking the problem goes deeper than that

[AnimalBabe]

Can you tell me what strength powerhead I should get for my 50 Gal tank? I don't know much about these, but was leaning towards the Maxijet 1200, which says it gives 295 gph. I was also looking though at the Marineland Penguin PH 550 or the 1140. I only have two clownfish and one damsel, no live rock, and an external canister filter. I'm also thinking of getting a dwarf angel soon.

Btw, do you know if you can add a biowheel to a canister filter? I read that they also help churn the water, but I'm not sure how much better or worse they would be. Thanks!

[Lorna]

I would seriously think about getting some live rock in the range of about 50lbs lose the canister filter and add 2 maxijets before adding any more fish. I would also look to add a good protein skimmer

[brooklynfish]

Originally Posted by Lorna

I would seriously think about getting some live rock in the range of about 50lbs lose the canister filter and add 2 maxijets before adding any more fish. I would also look to add a good protein skimmer

Agreed. Live rock is a must to any sw system. As for flow, a 1-3 MJ's would me fine. You could also go larger and get a Koralia 1, 2 ,or 3. I've heard some good things about them.

[quadZmoto]

Hi Guys. I am very new to the saltwater aquarium hobby but I am learning fast thanks to the posts within this forum.

I have a 120 gallon tank with a Euro Reef RS 135 Protein Skimmer and Quiet One 4400 HH Pump. To provide flow I am using two Koralia Hydor #4 Powerheads rated at 1,200 GPH each. I'm assuming with the powerheads and main pump I am moving about 3,400 GPH. I have one powerhead at each end of the tank mounted on the back and pointing towards the front about 4" to 5" below the surface. The outlets from the main pump are pointed towards the sides and front of the tank.

My questions are...

Do you think I have enough flow?

Should I rearrange my powerheads from the back of the tank and mount them to the sides?

Should I move the powerheads deeper in the water?

Should I purchase more powerheads in order to have a couple at the surface and a couple near the bottom?

Sorry for being so long winded just want to make sure that I have covered all my bases. Thanks in advance.

[Lotus]

It sounds like you have enough flow. Positioning/direction of the powerheads can take a little time. Make sure you don't have dead spots in the tank where there is no flow. It's a good idea to have at least one of the powerheads moving the surface of the water to help with oxygenation. If you have an overflow, have the powerheads positioned so the water naturally moves around then tank and then towards the overflow.