filtration and muck

Question
hello,
i currently have a 400 gallon pond but i will shortly be making it a 500 gallon pond by adding some out of ground concrete blocks. But anyway I have a 1200gph pondmaster pump and a tetra pond 2 bio filter. My bio filter leads to a small lets say 20 gallon pond about two feet above the surface of my main pond and then ther is a series fo water falls and streams. I have a section of my pond that i have placed rocks around that has about 15 waterhyacinths in and a couple of grasses. I also have about five water lilies. I have three koi two are about 11 inches and on is about 9". i also have approximately 10 goldfish and many mosquito fish.

Recently i have had a problem with about a quarter in layer of seemingly mud or some other brownish particle that covers the bottom of the main pond and it thinly covers the sides. every time i try do move something in the pond a clowd of this stuff dirties the water.I have tried several times to remove this but each year it build up again. I have recently been thinking of adding someother type of filtration like maybe a bottom drain or a skimmer. I wouldn't add a new pump just i would hook the one that i have to the new system. I also have a currently unused 350 gph pump in my garage that i could use. What would you advise me to do?

Answer
I am thinking that where the water lilies are planted that is where the muck is coming from. Try putting pea gravel over the dirt in the pots that the lillies are planted. you might also blow the dust of of the pump in tthe garage and use it as a small fountain if the problem persists

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