Conflicting advice on power heads

I just set up my first saltwater tank. It's 55 gallons. I have 70 pounds of live rock, a protein skimmer and a hang on the back power filter that is capable of 330 gph, according to the box. I introduced two clown fish a little over a week ago that seem to be doing quite well.

I'm going to a privately owned fish store where most of the associates seem to be quite knowledgeable. When I setup the tank the person helping me recommended a 160 gph power head, stating that this would be sufficient in conjunction with the power filter and protein skimmer. Then I read a book that recommend 5 - 10 times the tank volume in water circulation, or about 250 - 500 gph. So when I was in the store this weekend I asked a different associate about this, thinking I would put another 160 gph power head on the opposited side of the tank. He felt that was way undersized, but I can't remember what size he recommended.

So I bought a second powerhead, the same size as the first. One is mounted on the bottom right of the tank, blowing the water parallel to the back of the tank, directly left. The new one is on the bottom left of the tank blowing the water at a 45 degree angle to the right and front of the tank. I'm hoping this causes a circular flow.

OK, any suggestions. Is this, along with the power filter and protein skimmer sufficient? The output from both are several inches off the base of the tank. Are these good locations for the powerheads? Should they be at the same depth as each other or at different depths?

Thanks in advance.

BTW, I may decided to do a reef in the future, but that's probably a long time from now and should not affect my decision.

 

The advise I got when I started my tank was 20x tank volume, and I am currently running closer to 30x. Placement takes a little bit of playing with to get right. You want to avoid developing any "dead" areas in the tank, as they will allow waste build up and contribute to algae growth.

 

Wow!! 20 to 30 times, or about 1000 - 1500 gallons per hour. Does that include the power filter and protein skimmer, or is that in addition? How many power heads do I want? Should I augment the two 160 gph units, or replace them?

 

20 to 30X total flow. It's a good idea to have it in that range. Especially getting some flow through your rock. Stuff can get stuck in there and rot. It also helps the rock filter your water by passing the water through the bacteria in the rock.

 

Since dead spots seems to be the big issue it sounds like more heads of smaller size is better than a couple of larger ones, except for the possible problem of heat buildup (I've got to think that four smaller heads would produce more heat than two larger ones).

If I include my power filter I have approximately 650 gph flow. It sounds like I want 1000 - 1500 gph. I guess that means I want an additional 350 - 850 gph. Would it make sense to purchase two more, placing all four along the back - perhaps at a couple of different heights (bottom and half way up) and point them towards the live rock from different angles?

Right now I only have a couple of small clowns. This isn't going to overwhelm them will it.

One other question. Is the 20x - 30x tank volume appropriate for reef tanks, FOWLR or both? I would have thought that reef tanks need more flow than FOWLR, or is it that they both could use about the same, but it's more of a necessity for reef tanks?

 

The fish will be fine. They will probably avoid the direct outflow, but they might actually enjoy the current created elsewhere in the tank. The flow rates mentioned are appropriate for both FOWLR and reef. In a reef setting you do have to be careful about coral placement so that they do not get directly blasted by the outflow...they like simulated current, not simulated huricane.

 

More flow is always better. Up to the point it causes sand storms. Water flow should be at least 20x. I recommend 20x-40x the tank volume. This would include filters, skimmer, powerheads and return lines (if you have a sump).

 

I'm at about 9.5x flow right now without a protein skimmer. I've heard that anywhere from 10x to 20x is preferred.
I'm probably going to be getting another powerhead to push alittle more flow and get a protein skimmer soon as well.

Where do you guys suggest that powerheads be mounted - right now my one powerhead is pointed at my live rock 'pile' to give them constant flow. Do you guys think I should get another one and point it up at the surface?

 

I like to have flow across the surface. I have an out flow pointing toward the skimmer from the opposite end of the tank. It helps push the surface gunk towards the skimmer. I try to have a balance between surface movement and getting to wavy. Light penetrates smooth water better than rough so I try to get the surface moving but not too rough. Powerheads can be placed anywhere you think you need flow. I only use one but plan to have more soon. I want to use them to pull water through my live rock. I use 2 canister intakes now, but hope to eliminate atleast one of them. I'm going to cap off some UGF riser tubes and drill holes around the bottom so I can use powerheads to draw water through the rocks to the surface. An idea I got form Magpie Tears, I believe it was. That way I'll have circulation all through my rocks. I also want to setup 4 powerheads (2 on each side) to alternate back and forth every hour to switch the current back and forth. A little wave action if you will. I'm shooting for 25x in the end. I have 20 now and can say I definitely would like to get some more flow in to a couple spots. Mostly hard to reach areas in the rock pile.

 

Gozer has the right idea.
It does you no good to have live rock as a biological filter, if the water isn't flowing through them !

 

I am using the spraybar return from my canister to agitate the surface and keep my powerheads directed further down in the tank to be sure water is moving around/through the rocks.

 

Ok so rocks first, surface last. Got it.
Well I have the overflow from my power filter and an airstone agitating the surface so I will get another powerhead and hit the live rocks from another angle to get them more flow.
Thanks guys.

 

I am using the spraybar return from my canister to agitate the surface and keep my powerheads directed further down in the tank to be sure water is moving around/through the rocks.

Ditto

 

I currently have about 35X rotation on my tank.

The output is split into a "Y" which directs water at a downward angle across the back of the tank and then the other part of the y directs it to the front. Then, on either side of the tank I have two Koralia 3s which criss/cross eachothers current as well as the current coming from one side of the output, giving a kind of sideways tornado affect. I'm still probably going to get two smaller powerheads and place them on the back of my tank and their only job will be to blow detrus from the back of the rocks.