Pond Boss Forums AERATION Should I aerate? Shallow Pond Areation / Management ????

I have a .25 acre water retainment area that I am attempting to maintian on my property in Minnesota. The pond is generally shallow with a max depth of 4'. I installed a surface areator (fountain) early this spring and had a lot of success controlling the growth of Cattails and other aquatic plants. There is appoximately 1 ft. of muck at the bottom of the pond and I still suffered from nearly a full cover of duckweed. I have had recommendations to install a bottom diffused areation system to help control the muck and duckweed but am looking for more input before making any futher investments.

I doubt the bottom diffuser will be cost effective. I doubt the 4 ft deep pond in MN will stratify for very long esp if it receives a little wind action. Many "average" smaller ponds (0.25-1ac) naturally mix to a depth of around 6ft. If you want to make sure the mixing depth (turnover) occurs to the bottom, extend the intake tube of the surface aerator to about 1-1.5 ft above the bottom assuming the water level stays fairly constant. Strongly fluxuating water levels could cause the extension tube to extend into the sediments and cause mechanical problems.

If the pond receives 'regular' algal / herbicide applications it may be negatively impacting the natural decompositional flora of the sediments. Implementing a schedule of addition of sludge reducing bacteria may help with the decay of organic sediments. Sludge reducing bacteria will be more effective if the sediments are occassionally or regularly mixed infusing fresh water to them such as by raking or pulling some device through them.

Thanks for the advice I am reluctant to lengthen the intake hose as the water level does fluctuate. I have considered the use of bacteria and will look into raking as wel.

I have a similar size retention pond. My pond is about 7 feet deep, as opposed to 4. actually have an otterbine surface fountain thats centered. The problem I have is that each of the corners (one of them shallow) are still collecting a lot of sludge. I just drained the pond down about half way and I must have hauled out 2 tons of bottom muck/sludge that stunk of Anerobic bacteria. The center area of pond that gets the ripple from the otterbine looks great! No Much at all!
Would I benefit from adding bottom aeration near the inlet area that seems to be collecting the most muck?

Success has been acheived with a properly designed shallow water aeration system and pro-active approaches using bacteria that is facultative which contains both anerobic and aerobic bacteria. I have seen reductions in up to 5" per year of muck reduction and greater in southern regions of the U.S.

The greater the aerobic conditions the greater the reduction in muck. As for duckweed, 4 out of 10 lakes that I have worked on actually showed a great reduction in duck weed. We found that the pH changed so drastically to more of a neutrial vs high that the duckweed was not able to handle the neutral pH and was eliminated. I can not say that it always works but 4 out of 10 ponds it did work.