Some published test results from oxygen tests

[Samw]

Here are some test results from various tests that measure oxygen levels in the reef. You'll note that in his 10G tank, night time O2 levels dropped to 16% saturation when circulated by 2 powerheads only. When a skimmer was added, night time O2 levels increased to 81% saturation.

http://reefkeeping.com/issues/2005-08/eb/index.php

The results are consistent with the measurements that I took in this thread.

http://www.canreef.com/phpBB2/viewto...oxygen&start=0

The conclusions that are confirmed are:

-Aquaria can and do become hypoxic at night and such a state may pose a risk to hypoxia-intolerant organisms.

-Aquaria can and do become saturated or supersaturated with oxygen during the day, and this is a result of oxygen resulting from irradiance of photosynthetic organisms. In no case was saturation or supersaturation measured without photosynthesis.

-Airstones and skimmers appear to be a very effective means of oxygenating small water volumes.

-Powerheads and recirculating pumps do not appear to greatly increase the oxygen saturation state of seawater aquaria.

-Using algae in reverse daylight tanks appears to be an effective means of keeping oxygen levels at normoxic levels at night. This effect is pronounced even in tanks and systems that employ protein skimmers and airstones.

The test that I would like to see that he didn't perform is the effect of a skimmer in an overloaded 75G tank. In other words, I would like to see his 75G tank to be overloaded enough to bring night time saturation down to 16% (like his 10G tank). Then I am willing to guess that his skimmer would bring his saturation up considerably to around 60%.

[michika]

Great article!

Thanks!