Question
Hi, Glad to find you on the internet. My son and I took on a spring project and now we have a Koi pond. When we put the liner in the edges of the liner got muddy, then we had a water truck come in and fill our pond up appoximalty 1700 gallon pond. The liner mud is now on the bottom of the pond, it isn't alot, but the bottom of the liner is slick and you can see that there is dirt on the liner. I have read that some clay/dirt may be good for your Koi. Is this true? and what could we do to clean the pond up a bit. Thanks for your help.  

Answer
Hi,
Normaly koi ponds are filtered with a bacteriological filter which helps  to keep the water clear and in pristine condition which enables you to view your koi and also allows you to see if they have anything wrong with them so the mud really is a no no the clay that you have been told that is added to a koi pond is a special clay called montmorilite which adds minerals to the water which is then absorbed into the koi keeping them healthy and also making the colours better,BUT you do not have to add this clay to keep koi they will be quite happy without it.
I hope this helps. If you wish you can visit my pond at http://koi-z-are-us.20m.com
Regards George.