Should you measure Dissolved Oxygen in your reef tank?

[optimisticdingo]

When I was in High School my Science Club was in charge of monitoring a local freshwater stream. When we did our monthly water tests on the stream we always measured the Dissolved Oxygen levels and reported that to our State Department of Wildlife Conservation. However, in the aquarium hobby I haven't seen many people talking about DO levels in their tanks. Do you guys bother testing for it? If so, what levels are you looking for and what test do you use. If not, why not? Is this parameter not important? Just trying to learn more about reefing

 

[AutumnReefs]

I would say it would be handy if you are looking to breed fish. It may also be handy if you use a glass lid. It is hard to get people in this hobby to test critical things so trying to convince someone to do an oxygen test is most likely not going to go well unless they are very passionate about the science in their tank. I don't have a test for it but may get one eventually.


In other words, it is very uncommon.

 

[blasterman]

Wholesale fish farmers test O2 levels because they often have insane amounts of fish in a given tank.

Not worth it in a reef tank unless it's stupidly over stocked and you have zero water circulation. I mean zero.

CO2 on the other hand would be worth checking, if anything for experimental reasons.

 

[mdb_talon]

I dont test it and see no reason to for the average reef tank. Not that I dont think lack of oxygen is never an issue, but that for your standard setup with adequate flow and air exchange I dont think it is worth monitoring.

 

[Randy Holmes-Farley Verified Community Expert]

IMO, it would be a good measurement, yes, but unfortunately, DO meters are quite expensive. I've never spent the money on one.

FWIW, I suspect many folks would be surprised how low O2 drops at night. Most reefers overestimate the extent of aeration in their aquaria. If it aeration was complete, pH would not change day to night.

These have more:, including many studies on reef aquaria of various sorts:

http://www.reefkeeping.com/issues/2005-06/eb/index.php

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

http://www.reefkeeping.com/issues/2005-07/eb/index.php

 

[taricha]

IMO, If anyone is running an unskimmed system, or turns the skimmer off for part of the night, should definitely check the O2.

see this part of the second Borneman article Randy linked above.

The ten-gallon tank containing clownfish has been set up as an unskimmed system with what I consider to be an average stocking density of organisms for a tank of its size. I had assumed (wrongfully) that oxygen was maintained at high levels through the use of two powerheads that agitated the water's surface. However, once the lights went out and photosynthesis stopped, oxygen levels dropped quickly from a high of 78.7% of saturation to a hypoxic low of 16% of saturation. The levels were apparently low enough that each night, the clownfish would leave their anemone and adopt a position just under the water's surface directly above a powerhead. Out of concern, I then monitored the changes in oxygen levels at night using an airstone. Oxygen rose quickly and dramatically. At that point, I added a skimmer to the tank, with the result that oxygen is now maintained at much higher levels, ranging from a high of 130% of saturation to a low of 81.2% of saturation.

 

[Colin_S]

I was just thinking about DO levels in the tank and came across this thread. I see there is a Salifert test kit, but how accurate is it?
Has anyone published their DO level in their aquarium running a skimmer with good flow? that's the average set up, so would be interesting to see how much DO we should have compared to how much we need.
Anyone know of any other good ways of testing it?

 

[Randy Holmes-Farley Verified Community Expert]

I was just thinking about DO levels in the tank and came across this thread. I see there is a Salifert test kit, but how accurate is it?
Has anyone published their DO level in their aquarium running a skimmer with good flow? that's the average set up, so would be interesting to see how much DO we should have compared to how much we need.
Anyone know of any other good ways of testing it?

The article I posted above shows DO tests on a variety of tanks.

I'm not sure O2 kits are worthwhile.

 

[Malcontent]

Dissolved oxygen measurement is dominated by sensors. There are several types of sensors and several types of colorimetric/titration methods.

Measuring Dissolved Oxygen - Environmental Measurement Systems

Electrochemical or optical dissolved oxygen sensors are the modern and precise way to measure dissolved oxygen. Colorimetry and titration are other methods.

www.fondriest.com

I no longer have a skimmer otherwise I would have tested it by now. I did find a paper where the aeration ability of venturis was tested and maxed out at a specific aeration efficiency of 1.8 lbs O2/hp-h. That's about the same as surface aeration and several times less than what bubble aeration achieves.

 

[Colin_S]

better get my reading glasses