I have a well established and well cycled tank and untill 6 weeks ago a healthy stock.
I added 4 glass cat fish and they brought 'something' with it started on the golden barbs then to the others in tank, Soon all were itchy and so the tank was treated with Protozin( i have dojo loach and bara shark plus red tailed shark so that was best option) They all stopped itching and the patch of white just starting on goldens diaspeared.
In the last week 11 of the smallest fish in the tank have died and I have watched 3 and its the same way, they look like they are drowning and die opened mouthed...... I have a 320 l tank a 750 and 1000 w air pump split over 4 lines over tank.....( one bubble 3 air stones)
There are no fresh plants in as we have an old and grumpy algae eater who chews them and spits them out...
I suplement with algae wafers.. and the odd bit of blanched lettuice and spinach.
i know excessive mulm can cause fish do drown even in a well airatted tank but am unsure how to treat....
please help me I am particullaly as last night i lot my pregnant cherry barb who was very close to laying her eggs and I was really looking forward to her babies as she was on of my first fish.
thank you