How should Circulation in reef tanks be set?

[georgeortiz]

Water current in the reef tank are very important. However what should the optimum water movement entail. Should it involve a current affectiing the top middle and lower portions of the tank? Should only some portions of the tank have more current than the others. Much of it should depend on the species being kept but, what should the general rule of thumb be?

I have plumbed my 110 so I can utilized the return flow for water movement in various parts of the aquarium and control them with ball valves. This way I can avoid having to use power heads.

What are your thoughts on water movement? lets hear about your water movement schemas.

[Jimnorris]

Water movement on my tank is about 8,900 gallons a hour. Most of the flow is directed to the upper third of the tank. This is where the SPS corals are. The middle and bottom portion of the tank is set up to have a mild waterflow. I would like to add two Tunze streams (another 6,000 gph) in the left and right upper front corners of the tank.
But remember this is my tank and this type of waterflow is what is needed. I use one Mag 24, two Mag 1800s and 10 maxijet 1200s.
Jim

[Tim Marvin]

Oh yeh, and Jimbo's tank is over 200 gallons. I wouldn't recommend this flow if your tank is a 55.

[TAXMAN]

"wipes the sweat off his brow"

I was trying to figure out how to get that flow on my 58

HAHA J/K :lol2:

[eleyan]

Jim, 8,900 gallons a hour? Wow, the rule of thump I've read on other sites said 5-10 times the tank size, so for 200G it would be 1000-2000 GPH, you have about 40 times. You must have really fit fish :)
I also wanted to add more flow to my tank. I have a 72G with about 1000GPH, put after I posted a message about Cyano algae problem, I got a lot of feedback telling me to add more flow. The problem I was having is that I don't have a chiller on my tank and I'm already running 81 degree temp. So I'm afraid more pumps would raise this even more. I found the following site: http://www.globaldialog.com/~jrice/diy/wavemaker.htm
It has plans for building a wave maker. I ended up building one over the break. The cool thing about this is that the pumps are pulsed on a portion of the cycle, so they are not on 24 hours. That way my temp did not get effected much.

[matt]

The gph in a tank is not nearly as important as the flow characteristics. Random, changing flow is best; drop some food in the tank and watch how it travels in the currents. If it's moving pretty quickly throughout your whole tank in a somewhat unpredictable manner, that's good flow. Of course, the type of animals that you keep determine what's best for flow. It's always good to remember that there is basically no way we can duplicate the force and energy of water movement on a reef crest. So it's unlikely that we're subjecting our animals to "too much flow" no matter what we do.

[TAXMAN]

I have a 58 that has about 900 gph. I plan on a little more once I fix the overflow problem " Too Small ".. I want to get to about 1200-1400 without powerheads in the tank. But at 900 everything gets enough movement. So far no problems but it has been a pain trying to locate everything in just the right spots. Also get the book Aquaruim Corals by Eric H. Bornman. It shows A LOT of coral species and the conditions that they like to be kept in. It has been VERY helpfull to me since I am also new to Reefing.

Eleyan.
I have read in the same book that it is becoming more recomended to keep your water at 80-84 deg. The higher temps raise the motabolism of the tank as a whole, which is good. But be carefull not to go to much higher than 84. It is pretty close to the high limits of most corals.
I cant remember if it was Jim or Tim, but one of them has taken his chiller out of the system and chosen the higher temps.

Just my 2c worth.

Johnny

[Jimnorris]

It was I. My temp ranges from 79 to 86.
Jim

[matt]

Good call, Taxman, on the Borneman book. He's got an excellent section specifically on waster flow in the aquarium, probably the best thing I've seen written on this subject.

[TAXMAN]

Yea, that book has helped me more than anything.
( except you guys and gals ) ;-)

It's a must have. I read it a couple times a week to refresh myself and to find something I may have missed before.

Jim. How is the tank doing with the higher temps? Any change for the better? I dont cool my tank either. I also do not have a heater on it. It gets down to about 76-77 at night and up to 80-81 when the 400w shuts down.

[Tim Marvin]

I took my chiller out a while back. My temp runs about the same as Jim's. When you guys come over you'll see Jim's current. It sounds like a lot of flow, but it is actually very good. His corals are looking and growing great, and the substrate is still on the bottom.