View Full Version : Water Flow Question

08/17/2009, 09:56 AM
For info on the setup I have a 30 Gallon tank with 1 160 gph power head and a marineland emperor 350 hob. I am going to add a second powerhead when I convert to the sump (not sure what size yet).

I am building a sump that will consist of:

10 gallon tank - already have

Sock bracket and sock

Chaeto (wrapped in netting)

Light for the Chaeto

Return pump

Skimmer (At some point)

My questions are:

What return rate should the Pump be at? It'll be between three and four feet to the tank.

Also should my total water movement - including the powerheads be 10x the gallons in the 30 gallon tank or 10x of the total volume including the sump?

Lastly will a regular light work for the chaeto?



08/17/2009, 10:29 AM
Generally, you want your return to be about 4-5x your tank's volume. I can never remember whether or not that includes the sump volume, but anywhere from 120-200 gph should be just fine. It's more of a guide than any sort of hard and fast rule. You'll of course want to use the head loss calculator on the main page to figure out what type of pump will give you that amount of flow after head loss. I'm a big fan of Eheim pumps for a tank your size. They're quiet, energy efficient, reliable and not too expensive.

As for water movement in the display tank, 10-20x the display tank's volume (i.e. 30 gal.) is generally what you shoot for. It's very tank and powerhead dependent, though. For example, you can get away with much more flow if you use a propellar type powerhead like a Koralia than if you use a powerhead like a Maxijet that shoots the water out in a narrow stream. Also, the more rock and/or corals you have in your tank to obstruct flow, the more flow you'll need. It's really more about using diverse flow to eliminate deadspots without causing stress to any of your tank's inhabitants. . .in other words, a bit of trial and error.

And for your last question, I'm a big fan of buying one of the cheap aluminum clip-on shoplight reflectors from the hardware store along with a 26W screw-in power compact bulb. Look for a bulb that has a color spectrum rating of 6500K. It's not displayed on all bulbs, and it's sometimes hard to find, but I guarantee there's at least one brand that specifies that at your local hardware store. It's often branded a "daylight" bulb. Other bulbs will probably work, but I've had good success with those in particular. The whole setup should only cost you about $5.