Re: Help Please - Fish Deaths
#9
By red do you mean bright red or a ruddy brown, I get the latter in a wild life pond but I have never seen bright red algae.
To be honest it sounds as if the fish are in a fairly bad way and may be getting dropsy. You could try looking on
http://www.fishdoc.co.uk/index.htm but if they are as bad as they sound it may be kinder to kill them, clean and lightly bleach the pond then wash it out again to get rid of the bleach and then let it sit dry for a couple of days. Wash the pump and filter in tap water and start again but dont add fish for a month and then ONLY goldfish, 50UK gal is too small for koi. When looking to buy fish, they should be relatively active without prompting and the front fins should not be held tight to the body except when sprinting, the dorsal should also generally be up although this may go down when swimming.
If you can get pure ammonia from the chemist you may be able to cycle the filter prior to adding fish, read up on "fishless cycling" and I wouldnt add more than 4 fish. Most of my bought fish were under £1 each although I have paid £7 each for 2 6" sarassa comets but if you scan the goldfish tanks you can see sarassas that have slipped through the 'net'. I wouldnt mix new fish from different shops, buy from just one shop and perferably from 1 tank.
The pump is a bit on the small side, I would suggest 200lph plus you are unlikely to get full flow from a pump so your 125lph must have been running fairly close to the 1/2 a pond volume per hour which is the normally recommended minimum. '200lph' might allow you to drive a small fountain for added visual effect and oxygenation. All that I have read suggests inpond prefilters are a pain in the derrier however an external filter would be a bit of an over kill for a pond that size.
What oxygenators did you add and are there marginals etc? Test kits Aquarium Pharmeceuticals?? make liquid test kits that I think have a good colour range and that is important because you ae frequently otherwise trying to judge what shade of XXXXX you are looking at. They were about £5 at kit last time I bought them you want Ph, NO2, NO3 and NXx so £20. My first kit did all 3 for £11 and went in the bin because the colour scheme was rubbish