thanks for posting replies. koiphen.com, i decided on day of registration to leave it alone, JW thankyou for the offer, and jaimeb, very good advice. my pond 480litres, 9 goldfish. Not far off the amount of fish. New pond, weather permitting, 360 litres, will put 3 goldfish in, month later put another 3 in. My pump filters 700 litres an hour, both ponds, 5in1 3000 blagdon. 6 for new pond is right amount from what you told me. tkanks Blue.