Hi Pondboss, this is my first time here... I have been searching for info on aeration for the last couple of days and have not been able to find a good answer yet… I am hoping that this may be the right place to get some good guidance. I have 0.8 acre pond that I just bought from family along with an older house. The pond is around 17’ deep in the deepest and I am wanting to put diffused air into the pond at the deep point to try and get some aerobic digestion going for some of the organic material that has collected in there over the years and get a higher water quality in the pond for swimming. I want to determine the right sizing for aeration is... How many cfm should I be pumping in to the bottom of the pond. I know this is highly dependent on the BOD and that it changes through the year but I just want to find a good rule of thumb sizing guide. The pond has been there since the 40s and everything is still in good condition but organic material has built up on the bottom.

Welcome FlowRoll. You will need to look in the threads here for aeration. There is a wealth of information available. Many of the experts here have written on the subject. You might want to consult Sue Cruz with Vertex Aeration Systems. She is a very nice person, helpful, and as knowledgeable as anyone here. She is a factory representative but also a member of Pond Boss.

Thanks,
I will look up Vertex.

One thing I have seen on the forum is discussions about turnover. How does that work when you are pumping air? Is that measurement based on the amount of air I pump in a day?

Thanks

For an 0.8 ac 16'-17' deep pond try for a minimum of 3 CFM 10psi operational pressure. Your diffusers will require 8-9psi. Standard compressors for this task are rotary vane and rocking piston models. It takes 0.5 to 1 cfm to operate each single head diffuser. There are lots of threads in the Systems Questions Section that discuss DIY and package aeration kits. Also read through the Aeration section in the Common Pond Q&A Archives. Shape of the pond and ability of a diffuser to freely circulate from once central area to all areas will depend on shape of the pond. Two to three diffusers may be needed.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92494#Post92494

"..turnovers. Is that measurement based on the amount of air I pump in a day?"

Yes and no. Turnover rate, recommended of at least 1 per day, is based on how efficient the diffuser is. If you just blow air out the hose and make big bubbles it may take 3-5 days to create a turnover. The more water diffusers can move the faster the turnover. Vertex website has a graphic showing volume of water moved per diffuser style.

In smaller ponds than 1 ac, I personally like to oversize the system to produce a relatively quick turnover then shut the system off until the next day. Regularly resting the compressor allows it to last longer.
Run time each day actually depends on the BOD of the water body. BOD - biochemical oxygen demand. Practical - how fast the DO is consumed on the bottom.

Compressor working parts have a useful life span - depending on variables. A good quality compressor with adequate diffusers and 6-8 hrs operation per day should last you 20-30 yrs before the bearings go 'bad'. Air making rebuilds will be needed a couple time before the bearings wear out.

Thanks for the information. This is exactly the type of info I was looking for.