Thanks for that Margaret, just what I wanted to hear, ;) my Bro-in-law does have a very healthy pond and he breaks all the rules in the book, ::) he has three large Koi and several smaller that have been there many years, loads of gold fish and even more babies, his pond is bursting with plant life. :-\
The main pond raised high 2½ ft deep, has an area approx 5ft diameter that is circular with the water running down into a smaller circular pond approx 18 inches deep, wait for it, :D he has a pin hole leak in this pond liner and intends doing nothing about it and runs a hose permanently so gallons of untreated tap water must be in there, how does he get away with it? :o
Roy :)