Question
ihave a pond size 6x3x600 keeps going black on sides of pond can see fish but very murky water lilies are in pond but not growing to well any suggestion have clean pond out few times no difference thank you

Answer
Dear Robyn,

To now for sure I need to know which type of filtering you use.
First you need A prefiltering.
This will remove the visual debris.
Then A bacterial filter.
After this I advice A UV lamp.
This should be the base for filtering A pond.
Is this in place and can you tell more about the size of it?

Good luck!
Warm regards,
Raf