What is the brownish green stuff growing in my koi pond?

Question

I need more info on Pond muck and sludge pellets especially to know if it will solve my problem in my koi pond!

I have a 1,000 gallon natural Koi pond.  The bottom and the rocks are covered with this brown crud, muck, sludge, I don't know the actual name of it.  My water is clear, but the bottom is so ugly it takes away from the look of the pond.  I wanted a natural pond, but now not so sure. Will you pellets help get rid of this stuff?

I put in a small aquascape bacteria pellet each week to no avail.  I have also tried the once a month bacterial puck I got from ebay.  I add algecide once a week 1/4 cup.  That's it! 

I had to cut back most of my plants this summer because I was attacked by a mink, and I had to find where he was getting in through the netting. I know plants help with the muck, but not that much.  I have always been plagued by the muck. 

The mink took out 11 of my koi, even though I had the pond netted.  The netting had 2 inch holes, which is how he got in.  I also had the netting pinned with garden stakes every 10 inches or so.  I just put a new net over the old net with holes the size of a penny.  So, the mink has not been able to penetrate.  Whew! 

These are pictures of the muck I took when I went down to feed the few fish I have left.  :(

 I'm afraid you really can't see the muck in the pictures because of the netting.  It is just a substance, not unlike dust.  When I try to hose it and send it to the filter,  it rises, swirls around and then settles back again. 



Some does go to the filter outflow, so I am able to get some of it.  It is a brownish greenish color and appears to be growing on everything, but it doesn't stick.  Just settles and looks gross. Mushy like stuff.

Any answers?

N. N.
Newport, R.I.

Answer 1

Hello,

It is a bit difficult to see the pond through the netting but it does appear to be the typical brownish plantlike algae growtjh that adheres to rocks and stones and will buildup on liners in pond as well.

One good technique to keep mink, racoons and other predators out of the pond is using one of the motion dector sprinkler systems. They connect to a garden hose and have an adjustable motion detector eye that will turn the sprinkler jet on when motion is detected and send a powerful jet of water towards the area being targetted as well as a shrill sprinkler sound that will scare anything that gets close to the pond. I have one in my own backyard to protect the pond from the racoons who like to harass my koi and it works great, have never had a fish touched since I got the Yard Enforcer.

For the growth on the pond bottom you should try a liquid bacteria like the EcoLaboratories PL bacteria which helps create an enhanced biofilter environment in your pond filter which will accelerate the breakdown of organics in your water column. In combination with this they also make a product called Sludge Away which is a liquid that speeds up the removal of muck and this muck reduction will assist in the reduction of the green growth on rocks and in streams.

There is a combination package containing 1 gallon of the PL and one gallon of the SA (sludge away) from microbelift and these are an ideal additive to keep ponds clear and clean. They are also safe for fish, plants and birds.

In large natural ponds a muck pellet like AquaFix might be the best solution as it contains barley straw as well as bacterial enzymes but in a small koi pond like you have with mainly rocks on the bottom and a lined stream then your best bet is using a liquid product that will enhance your existing filtration system.

Please send me details by email of your pond filter system and I can ensure it is properly sized for the pond and fish load.

To help keep your fish friends in security I would look at the sprinkler to deter predators as I know how disheartening it can be when a pond is raided by predators and our prized fish are eaten or killed.