I have a pond that had regular 5ft-6ft of water clarity. The pond was 90ftX90ft. 8100sqft, It was too clear and that allowed algae and weeds to grow on the bottom in 8ft of water. Knowing what I know about fish and water biology, I in the spring 2 years ago put one 8" koi in the pond. This past year the koi is now 20"-21" long and water clarity all summer was constantly 12"-13" - no more 5ft of clarity. No more algae nor weeds. Knowing this what do you think 4 or 5 adult koi would do to a organic sediment layer in a smaller liner murky bottom pond? Your water clarity problem is due to koi. They are bottom rooting fish who for many hours a day are searching the sediments for food items. Because your pond is in FL and water is warm about all year and the koi search bottom sediments roiling the water almost every day about all day for food. The fewer koi that are in the pond the clearer the water will become.

There are ponds with koi that have clear water. These ponds have extensive, elaborate and very expensive water filtration systems. The clear water koi ponds also almost always have rubber liner or cement bottoms that have minimal or no bottom materials due to extensive types of filtration. Thus koi have little if any bottom materials to roil the water; filtration removes what little sediment that accumulates.

With your current pond conditions you will likely not see algae blooms because the high amount of suspended sediment prevents light penetration to most all the pond bottom and only light gets to shallow water about 12" deep.. Plants including algae need light to grow. No light, no growth.

Get rid of ALL the koi and any other bottom feeding fish and water will quickly clear to 5 ft deep however the pond will be filled with plants and way too much algae due to years of nutrient accumulation and sunlight penetrating to all bottom areas = Lots of plant growth.

Talk to numerous members of your local koi association or operators of clear water ponds with several adult koi and they will tell you what it requires to have clear water with adult koi present. Dirt bottom ponds and koi do not result in clear water. As long as even 1 koi is in your small shallow 0.1ac pond expect water clarity to be not much better than 10"- 12" with your small scale filtration system. However the good thing is with this turbid water, you should not have very much problem with filamentous string algae and submerged bottom weeds.

Last edited by Bill Cody; 12/04/22 02:53 PM.

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