This is probably not the best place to ask this question but I can't find much useful info. on the interweb. I know lots of you dabble in aquaponics as well as aquaculture so maybe someone will be able to help. I have an RAS that I have reached my limit without adding additional oxygen in some way shape or form( besides traditional air stones.) I have considered getting a refurbished oxygen concentrator but have my doubts about it being able to push enough pressure to run an air stone. My water is about 4 feet deep and the concentrator runs 5 LPM at 6 PSI. Does this sound like it will work? Do you think it will really make that much of a noticeable difference in my O2 levels? Just curious to hear some of your thoughts. Thanks

You are talking about a downflow oxygen contactor correct?

I do not think that your current setup will work at only 6 PSI. Would you be delivering oxygen or atmospheric air to the concentrator? I can post pictures and describe how to build one if needed, but it will require at least 25-30 PSI of air pressure to bubble an airstone inside the apparatus and compressed oxygen is needed.

How big is the tank?

No I am sorry. I should have been more detailed. It is a medical grade oxygen concentrator. I see them used a lot for glass blowing and have read of a few people using them for aquaculture but the details are limited. They produce about 93% pure oxygen from atmospheric air. My system consist of 2,000 gallons, 14 cubic feet of Kalnes bio media, and a 1800 gph pressure pump and filter filled with xtreme fine bio media. All has been really well so far. I have probably about 600 lbs of tilapia but my oxygen levels are starting to struggle.

Could you run the output of your oxygen generator into the intake of your traditional air pump for your air stones? This would just increase the O2 content of the atmospheric air going into a conventional air pump. The air pump would need to have components capable of handling whatever the enriched O2 percentage air resulted.

93% oxygen can be a fire hazard. Be very careful as a spark in the wrong place could create a disaster.

http://www.modernhealthcare.com/article/20140715/BLOG/307159995

Pure oxygen is best when it uses micro bubble airstones, and they typically need high pressures ~25 psi to flow. If you add pure oxygen through high flow airstones with large bubbles, most of the O2 is lost to the atmospheric air, especially if you are still using aeration in the tank.

There is a big difference between aeration and oxygenation.


Have you thought about going to an airlift system?