Cloudy water

by David Walker
(Bolton, England.)

I've recently fitted a new filter box with UV light to my pond. I used my old pump & would estimate it fill the pond in 2hrs. The ponds approx 9' x 7' and 3.5 feet deep at its deepest. The pump runs 24hrs. My problem is that after approx 2weeks the water went cloudy again. I've tried a product called 'hydra crystal' which had short term effects. I've also put a bundle of barley straw in at one end & I've created some shade so the pond gets sunlight for 50% of the time as opposed to most of the day as before. We have 3/4 potted lilly plants on the bottom of the pond thats produced approx 25 lilly pads. The pond was filled on 12th May 2009.
What may be contributing to the murky water is overstocking.we originaly had 18 Koi, but recently a friend filled his pond in & asked me to take his 10 shubumkins in. The koi are 6-7" and the shubumkins 3-5".
The only time we see the fish now is feeding time!!Any advice or help in helping to make water clear again would be greatly appreciated.

Many thanks in advance,

Dave


Doug says that if your bioload is too high (too many fish) then not much is going to clear up the water unless you increase the filtration or reduce the bioload. That many fish will also be stirring up the water (mechanically) so that any sediment on the bottom is going to be put into suspension (increased filtration necessary)

If you have a functioning UV filter sized for the pump flow, then algae shouldn't be a problem. Sounds like a suspension solids problem at first glance - reduce the fish load or increase the filtration rate/surface area.