How to increase Oxygen

[pitons]

The Oxygen level in my 72 gallon reef tank is always low. I'm using the Salifert O2 Profi-Test and it barely registers on the scale at 2 mg/l.
All other water parameters seem fine.
I have tried increasing circulation, pointing a powerhead toward the water surface to create ripples, etc., but nothing seems to help.
Any ideas?

 

[stupid_naso]

You can add another power head. Or that little oxygen pump thing, that creates air bubble. My friend has an eclipse 40 with the power head and the extra pump.
sebae_the_clown

 

[broomer5]

Best I've ever gotten with that same test kit is 5 mg/l. Not really sure if the kit is accurate.
I've read some things by Albert Thiel and will try to summerize here.
Anerobic bacteria use O2
Temperature affects the amount of O2 in your water. Higher temps = less O2
Thiel recommends 75-77 F
Fish respiration reduces O2
Decay of organic matter reduces O2
Unclean filters reduce O2
Overfeeding reduces O2
Overcrowding reduced O2
Using a protein skimmer increases O2
Good water movement at surface increases O2
Algae increase O2
He states that any level below 7 mg/l is worth looking into the above, and trying to make changes.
Again - not 100% sure the Salifert test is accurate - I have not compared it to any other kit.
What temperature are you running your tank at ?
Not much help I know - but what the heck.

 

[fish]

I cycle my tank water about 10 times per hour. If you have a 72 gallon you need to be moving about 10 times that through your pump system. I have found that this will right your tank.
Good Luck!
Fish

 

[pitons]

Thanks for the info.
I keep the tank at about 78 degrees. I have 4 powerheads in the tank and when I calculated the gallons/hr circulation it was just over 10X my tank size, so I thought it was pretty decent.
Maybe I'll try another brand of O2 test kit.