Question
Hi. My question is regarding my new fish pond. My husband installed a 90 gallon pond on Wednesday, August 18. Well he also put 12 fish in it that night. They appeared to be fine, on my way home Thursday, I stopped and bought Algae Blocker for FISH Ponds. By Sunday morning, 4 were dead. He went to buy 7 more fish, got home and the remaining fish from earlier were dead. Took them out and put the new ones in, 2 hours later they were all dead. What could be the cause of this? There is conditioner, clarifier and algae blocker in the pond. Should there be shade or something else? Please help. Never killed fish before...

Answer
When fish die that quick, it's usually from poisoning.  What was this algae blocker?  Could it have been overdosed?  Even if not, many algaecides are dangerous for fish.  Do a 100% water change and add dechlorinator and maybe salt (no other chemicals), let the water sit for a few days, and then try again.  Also, check your pH levels.  Did the pond have aeration?  What signs did the fish show?  It's also possible the fish were ill when you got them but it doesn't sound like that.  Good luck!

Robyn
fishpondinfo.com