Oxygen availability/saturation in marine aquariums.

This is best observed via algae and cyano bacteria retaining bubbles with in the cellulose or with cyano, with in its membrane.

The larger these bubbles can achieve in size before release, the more oxygen is saturating your tank water.

The saturated oxygen dictates when these bubbles will releaese, when there is quite a lot of available oxygen in your tanks waters these oxygen bubbles are repelled and only release when the drag of the bubble is to great for the cellulose or membrane and is no longer strong enough to hold onto these bubbles.

Saltwater, if relatively free of impurities and at a salinity of 1.025,which is the oceans normal salinity in open ocean, absorbs available oxygen from the air along with any other gases in the room at the time, to around 5 mill of depth in the water with out you doing anything, just letting the water sit in an unsealed container achieves this.

The circulation of the tanks waters achieves oxygen moved from the surface to the lower reaches.

The main disrupters of oxygen saturation are-
1.Temperature of water above 25c will begin to reduce available oxygen and become critical at 30c.
2.Ammonia will render oxygen toxic to aquarium life, more so fish.
3.Inadiquat current moving surface waters in the aquarium in a motion from top to bottom.
4.High levels of organic substances at the surface of the aquarium due to no,or low surface skimming.