Water Movement

superswamper · 12-23-2003, 04:44 PM

We currently have a 75 g FOWLR. My concern is about water movement. I hear (see) everybody talking about wave makers and powerheads, and am starting to wonder if I'm missing the boat. I'm a little obsessive compulsive about worrying about it, so I hope you guys can put my mind at ease.

We have a skimmer and a filstar xp2 canister filter producing our water movement. Do we need additional items (i.e. powerheads) for more movements? Thanks guys.

RWD · 12-23-2003, 05:31 PM

What is the turnover rate of both of those filters? In other words, home many times do they pump the 75 gal through them per hour? A good rule of thumb is about 10 times tank volume per hour (10x75 gal.) MINIMUM. Some reefers on this board are at 40+ times per hour. Good circulation is very important, more important then most people realize. What are you keeping in the tank?
Bob

kram138 · 12-23-2003, 05:54 PM

In a fish only system, water movement is far less important than in a mini reef. Like RWD said, water movement is absolutely needed and under appreciated in all systems with coral. Proper current both removes waste from the sessile invertabrates as and brings food and nutriants to them. That's not the only reason water movement is important in a reef system but it is probably the most important.

Your system should be ok, not great, with the flow from the skimmer and the canister. The biggest reason to add more water movement to a fish only system is keep waste and excess food suspended in the water column so it can be exported through your two filters. This will cut down on any algae problems you might have as well as add to the general health of the system. I have seen fish only systems run sucessfully with only a skimmer. Now, those people spent a great deal of time cleaning all detrius and any uneaten food.

So, bottom line. Not absolutely required in your system. But it couldn't hurt.

PS, unless you will be adding corals, don't worry about a wavemaker. A couple of powerheads at opposite ends of the tank will do. Hook them up to cheap light timers if you want less laminar flow. HTH

superswamper · 12-26-2003, 10:15 AM

The xp2 generates 300 gph. I'm not sure about the skimmer, though. Leaving it out of the equation will give me a little cushion if I get the turnover to 750 gph. I was thinking about getting two maxijet 1200's and placing them on opposite sides of the tank, and aiming them towards the middle of the tank. With the addition of the two power heads, we'd be at around 900 gph.

I have noticed a 'film' on the surface of the water, which I understand to be DOC, so I think we need some more movement.

The current residents are: 2 clowns, 1 yellow tail damsel, 1 six-line wrasse, 1 chalk bass, 1 banded goby, 2 cleaner shrimp, and 1 african star.