<a href=showthread.php?s=&postid=11383550#post11383550 target=_blank>Originally posted</a> by Machado deSousa
Hi fatrip!
We can dissolve oxygen in the system in various ways through the water surface in contact with air. When I projected my setup I decided a largest possible area of the tanks in contact with air, the same is to say I select the least highness possible both in aquariums and in sumps. I enrich water promoting the movements of the water and avoiding stagnant zones and stratification so that the upper surface layers, rich in oxygen, are permanently replaced by the lower layers that contain less oxygen. I trust also in overflows, in cascades and falls of the water to dissolve oxygen to my system. I use a ceiling fan working 24/24 hours to further improve O2 concentrations in the water. Through algae filters, because i have a significant mass with lights on 24/24 hours, i can dissolve more and more oxygen in the water reaching over saturation levels.
About the contribution of skimmers in the oxygenation, some authors are of the opinion that due the surface tension of micro bubbles with organic matter they attract prevents the exchange of oxygen between the air and water, moreover flow-through rates are normally relatively low.
What I have just said about skimmers is true relatively to the kind of skimmers we use in Europe. I have a completely different idea about downdraft skimmers, widely used in the USA, because of their height and high flow-through rates and the use of cascade that confer on high capacity to increase the dissolved oxygen.
Cheers,