ULN O2 levels

[m2434]

As shown by Eric Borneman (http://reefkeeping.com/issues/2005-08/eb/index.php) In a "normal" nutrient system, photosynthesis provides a big chunk of the O2. However, in n an ULN system do you guys think this is actually true?

I've seen a number of posts now where people suggest carbon dosing during the day when O2 levels are higher. However, how much higher are they in an ULN system? It would seem that the O2 will be directly related to the available nutrients and this O2 generating mechanism should then be significantly reduced with ULN levels.

It would be interesting to reexamine Eric's experiments with a ULN tank. I suspect that the primary mechanism for introduction of O2 would shift from photosynthesis to primarily the skimmer and surface area. However, has anyone looked at day/night O2 levels in a ULN system? Or even compared O2 levels in a ULN system to those in a normal nutrient systems?

 

[Randy Holmes-Farley]

I've not seen any O2 data on ULNS systems, especially those so low that it is restricting zoox levels, and an unskimmed UNLS system using carbon dosing might be among the worst potential problem situations.

 

[bertoni]

I haven't seen any data on the subject, either. It's an interesting question.

 

[m2434]

hmm... wish I had an O2 monitor Seems like it definitely could be a problem in some systems, even without any significant bacterial blooms. People always say a protein skimmer is required in a carbon dosed system, to remove bacteria, bacterial byproducts and to aerate the water because the the bacteria will consume O2. However, thinking about it, it may actually be a double or triple whammy, with regards to O2 even. The bacteria will consume O2, there is less nutrients, so, algae will produce less O2 and possibly the bacteria will out-compete the algae for what little nutrients are remaining.

In my new system, I merged a few nano systems into one larger system. I still didn't have nearly enough rock though. So, i used a lot of dry rock. I had been carbon dosing in the nanos, so I decided to continue in the combined system. I've found it somewhat incredible to see how long it's taking for the rocks to get algae covered. I've always used baserock, but usually a few months in, as I am now, the rocks are looking pretty covered in micro algae of various sorts. In this system, there is some, but a fraction of what I'd expect. So, I can't imagine there's much O2 being produced.