Tank Discoloration And Dead Fish

I have owned an aquarium for over 30 years. In the last couple of years I have experienced a severe problem with water clarity that eventually results in fishing dying. Initially the water fails to clear after vacuuming the bottom, this gets progressively worst with each cleaning. Soon the water begins to turn greenish and apparently becomes toxic as fish begin to die. The fish have a reddish hue and looks like blood shot eyes.

So far algae treatment does not work, and frequent water changes do not do anything.

Any advice or if you have experienced this I would love to discuss.
Thanks
Mick

 

Are you testing your water? Your ammonia, nitrite and nitrate levels should give you an idea what's going on.

 

I agree. the other one I'm curious about is pH ("old tank syndrome") . if that's dropping to 6, then I'm curious about kH.

while you're testing your tank water parameters, you may also want to check your source water (tap) parameters.