Point to Measuring Dissolved Oxygen?

[aninjaatemyshoe]

This is something I've been wondering for awhile and I've not been able to think of a good answer. Some advanced aquarium controllers out there (like the Aquacontroller III Pro) have the ability to measure dissolved oxygen. Why? I mean, I understand that dissolved oxygen is very important for most any aquarium inhabitant that one would keep. But if someone was worried about not delivering enough, they could just add add a good sized protein skimmer, or use more water movement, or add a refugium, or any of the myriad ways of increasing oxygen in ones system. You could even go way overboard with this, I don't think it is possible to introduce too much oxygen through the traditional methods. So why bother with measuring it if you could just focus on maximizing it? I don't see that knowing the number facilitates this in any manner considering that we're not concerned with introducing too much oxygen. Also, doesn't measuring ORP typically give a good enough incite into how much oxygen is in a system?

[LockeOak]

The only reasons I could think of having a dissolved oxygen meter is if you were working with an unusually high bioload, breeding fish for example, or with a tank of very unusual dimensions, tall with a small surface. I would imagine if you had 100 juvenile clownfish in a 20G tank or something like that then measuring O2 might be helpful. I don't know of any reason to measure it in a "normal" reef tank. Maybe if the power were off for some reason (of course, so would your controller).

[HDAlien]

Not necessarily, the ACIIIpro has provisions for two power supplies. I have one hooked up to UPS and the other on non-UPS so I can get the e-mail if I lose power at my house. And yes, I do have the O2 probe for my system, it's a pain to calibrate BTW.

[dendro982]

Or during Melafix-Pimafix or vodka treatment, when additional aeration was mentioned as useful.

[Wryknow]

If you're having Ph issues it might be nice to know how much of it is caused by alk availibility and how much is caused by low O2 levels I suppose. It seem s like an awful lot of money to me for something of marginal value. I guess you could get an O2 tank and add O2 but that seems like too big of a fire hazard to keep in a house to me.

[m2434]

Originally posted by Wryknow
If you're having Ph issues it might be nice to know how much of it is caused by alk availibility and how much is caused by low O2 levels I suppose. It seem s like an awful lot of money to me for something of marginal value. I guess you could get an O2 tank and add O2 but that seems like too big of a fire hazard to keep in a house to me.

How does O2 affect/effect pH? The only thing I can think of is it would have effect metabolic activity and subsequent CO2 production.

[billsreef]

O2 doesn't effect pH, it's the CO2 that does

I'd also agree with the sentiment that there is no real reason to test O2 levels on the average tank.

[Wryknow]

I was thinking about how low Ph is frequently caused by excess CO2 (and poor aeration) and hypothesizing that perhaps monitoring the O2 levels would be an indirect monitor of aeration. I vaguely recall that I got a C in organic chemistry though so I suppose that my meanderings are not necessarily valid on this point.

[aninjaatemyshoe]

I suppose that low O2 often means high CO2, but this is not always the case. At high altitudes, for instance, you would expect the O2 and CO2 levels to be lower than at sea level. Measuring O2 would not be a good enough indicator of CO2 levels.

I think the need to measure dissolved O2 levels is pretty much only for commercial fisheries and the like. For the hobbiest tank, there is no point.

[Randy Holmes-Farley]

I wouldn't measure O2 unless you had reason to suspect it was low.


Also, doesn't measuring ORP typically give a good enough incite into how much oxygen is in a system?

No, ORP says nothing about O2.

I was thinking about how low Ph is frequently caused by excess CO2 (and poor aeration) and hypothesizing that perhaps monitoring the O2 levels would be an indirect monitor of aeration.

Not really. Tanks can have high and low CO2 that are independent of O2 since not all processes impact both (limewater, for example).