Excellent thanks! I am growing outdoors and the problem is using standard air pumps outside in possible rain, I have brought a fairly powerful submersible air
pump that I am going to use in my reservoir and the pump itself has a attachment that sucks air through a tube and mixes it with the water (multi 4000
http://www.sicce.com/foto/prodotti_allegati_74.pdf ), I will try this out and see if it going to produce enough oxygen. Thanks again.