Is it Oxygen Saturation or Water Flow?

[dbsherwood]

I've seen lots of information out there over the last few years about how you need to have really high water flow to grow SPS corals well due to the respiratory needs of the corals etc.

Currently in my tank I only run 1 12 amp pump that pushes water lengthwise across my 8' long x 4' wide x 3' tall tank. The water then goes down one story into my basement into a detritus trap, where it has gaseous exchange twice (once when it falls in, once when it falls out), then into my sump, where there is further gaseous exchange. The skimmer also provides for air exchange. Finally, a fan linked to the outside blows exterior air across the tank, providing for fresh air exhcange.

The point I'd like to consider is this: shouldn't respiration be considered as a combination of dissolved gases in the water as well as the water flow, and if you have excellent gas exchange, shouldn't that mean that less water flow be required across the corals? In short, don't both matter, and don't you just need an optimal combination of the two? If you don't have excellent gaseous exchange, you're going to need higher water flow, and vice versa.

Thoughts? Thanks.

 

[Anonymous]

In reef tank gas exchange, there are two interfaces. The air/water interface and the water/cell interface. The circulation of water links the interfaces together. So to get efficient gas exchange, you need to have both circulation *AND* "respiratin". Does that help your question?

 

[Len]

A recent article in www.advancedaquarist.com (don't remember when it was published, but it was a Featured Article by Dana Riddle) also suggest high flow is important for temperature regulation. Corals can get too hot from the light energy as well, leading to such things as bleaching.