that sounds very interesting, your not the only one with this problem but might be one of the few that has a great idea around it... do you have a link to any of your info on it or care to elaborate a little more? i know you have me thinking..Lol I have a ph issue now. But I use an air drive skimmer so no Venturi to pull air in with. I went round and round over how to get my air pump to draw outside air. I saw a neighbors kid put a toy in a Tupperware. So I copied him, I copied a 3 year old. I bought a air tight flour/sugar container and installed a 1/2 in hose barb into the lid and used silicone to seal it. I run the hose out the window and the air pump in my room feeds my skimmer fresh air