Pond was built in 2009. It’s 2 1/2 acres, 28 feet maximum depth. The fish grew very rapidly the first 3 to 5 years but are now stunted despite harvesting fish every year. When our house was built in 2012, the septic system was not designed properly and started leaking water into the pond in 2013. Over the years with high nutrients, the pond has now turned clear with lots of filamentous algae growth.

I always had planned to aerate this pond, but kept putting it off. But I guess now is the time to aerate to try and reduce the nutrient level in the pond. I am getting the septic system fixed but I want to design an aeration system for the pond. I have a geothermal heat pump for my house and the coils are at approximately 24 feet deep in the pond. I plan on placing the diffuser at around 17 feet deep. I have a RockR air compressor, and I will get the details posted tomorrow of that pump. I would like to know the best diffusers and line to run.

The pump is a WobL 607ca22

Chad, looking at the specs on your pump, it is a very low output...only .78 cfm. That will only operate one membrane diffuser(operating range of .5-5 cfm)...not nearly enough to aerate your pond. It's been years, but IIRC, your pond is pretty round. You should be able to get a good water mix with a matched, quality system. You could also benefit from adding Alum to bind up the excess phosphorous in your water to prevent/reduce future FA growth. Give me call if you'd like more options specific to your BOW

Just to add to Rainman's comments regarding pump size...if you put your diffusers at 17 feet, that puts the head pressure at 8.5 psi (1/2 psi for foot of water depth). Plus about 1 psi for the diffusers and another for the losses in the lines. This equals 10.5 psi...the output of the 607ca22 would be just under 0.69. I would say you could run one diffuser, but only marginally at best. Generally speaking, Look into a pump that puts out at least 1 CFM PER diffuser at 10 psi , preferably one that pushes a bit more depending on the brand of diffuser you go with. NOTE: Rainman mentions diffusers that can put out 5 CFM per diffuser.

Here is a thread that really gets into some pump number crunching if you care to get deeper into it...

http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=491549&Board=11

As far a diffusers and line sizes...Vertex diffusers are very popular and the size of lines will be determined by the length and quantity of the lines. A typical system would have 3/4 to 1" mainline with 5/8" ID sinking lines to the diffusers, but you'll need to give more info to determine how typical your system will be.

Thanks for the replies. After posting, I realized this pump would be way too weak. If I decide to aerate, I guess I will need some professional help to select the right size system.

The problem I’m having is the water is too clear and FA growth is too much. When I say clear, I mean 10 foot visibility last summer. It’s not quite as clear now due to recent rains and run in. I can’t figure it out because the first 8 years the pond had a perfect 12-15” visibility with good plankton blooms. Then bam, last winter went clear. I did some tests today;
temp-47, pH-7.3, ammonia nitrogen-0.1, nitrite nitrogen-.03, alkalinity-20, hardness-20.

I had AG lime spread over the pond last summer, about 10 tons.

Any ideas?

BTW, my septic system wasn’t installed right and septic water has been trickling into the pond since 2012. I’m getting it fixed this month. Don’t know if that has anything to do with the clear water or not.