The bigger the koi get the more muddy water they create. There may be enough koi to do enough in cold water to keep the water clarity 2ft soon after after ice out. IMO 3 grass carp by themselves in 1/4 ac would result in water clarity of around 2 to 3 ft. Too many grass carp can also reduce water clarity. Koi also help to keep sediments rototilled and mixed keeping weeds and algae from growing.

I don't think that moving the air diffusers up off the bottom will not do much to improve water clarity. Try it and see what happens and report back here on this thread. We can learn from your testing. The major or strongest mixing of pond water is at the top surface boil action as it spreads and pushes outward the water entrained from the upwelling water column.

You think they (koi) will just forage in deeper water? Yes - deeper water foraging. It is instinctive for koi to root and dig in the sediments where ever they can find food. Feeding them pellets might keep them more full of food resulting in less digging action????

If it was my pond I would watch YouTube videos how to catch carp. Bait them regularly (daily) and fish in the baited areas on weekends and remove as many as you can catch. Have a carp fishing party for family (friends) with prizes for biggest smallest and most koi caught. The fewer and smaller the koi are the less turbidity will be in the pond. IMO a 1/4 pond should have only one large koi and one grass carp. Based on plant / algae growth, One or two can always be added if needed but it is very very hard to get them out.

Last edited by Bill Cody; 08/12/24 08:09 PM.
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