Pond Boss Forums AERATION Systems questions Aeration: 24/7 or 12 on 12 off

This topic will be explained this weekend on Saturday morning at the Pond Boss Conferernce IV at Big Cedar Lodge, Branson, MO. Topic of "Do Ponds Really Need 24 hr Aeration" by Bob Lusk. You should try to attend. There will be lots of VERY good information on many topics for new pondowners.

Not feeding the fish nor fertilizing will help in allowing for shorter aeration run times than 24/7. A new pond also helps. As the pond ages expect to run aerator longer each day especially in mid summer or whenever the water is above 80F at the surface because the dissolved oxygen requirements of the entire pond (oxygen budget)increase as the pond ages and accumulates more nutrients, plants and organics. Also as water warms it cannot hold or absorb as much oxygen. In warmer water the DO is lost or consumed faster, thus it useds more DO per day. There are numerous "it all depends" with each pond and aerator run times.

Ideally to answer your question one should measure dissolved oxygen (DO) at the bottom of the pond. The goal IMO of every aeration system is to maintain DO ABOVE a bare minimum of 1mg/L or 1ppm. Higher DO than 1.0 is MUCH BETTER. For good fish life DO should be a minimum of 3-4ppm. But IMO one's goal should be to maintain enough DO to keep aerobic bacteria and invertebrates alive in the bottom surface sediments. DO meters are expensive - $350-$800. Often (at least in northern areas) one can 'measure' the amount of mixing at the pond bottom by monitoring the bottom water temperature and comparing it to the surface temperature. Get yourself an electronic digital thermometer with small probe with cable. These are most commonly available with ten ft cables. I think two cables can be spliced and water proofed with silicone sealer. Once cables are spliced, calibrate the unit with a standard thermometer. Check one bay for fishing temperature meters, some will longer cables of 20ft or more.

Now for the unknown. The following method is not without risk. In my experience with bottom aeration, if the bottom water is kept within 3-4F deg. of the surface water, one can assume adequate mixing with at least some DO on the bottom. Run aerator enough daily to achieve this temperature similarity between top and bottom. Well mixdponds will have only 1F difference between top and bottom temps. NOTE this probably will not be true for fertilized or eutrophic ponds. Other experts, especialy in areas south of Ohio should verify this concept. Also to be safe and do NOT believe this blindly, you should have your DO actually measured in mid-summer while using this philosophy or technique by someone with a DO meter.