Dying tank

[menorcaman]

Hi everyone.
I have a puzzling problem. I have had tropicals for five years now without any major problems, UNTIL NOW. Up to two days ago everything was fine until my silver shark got popeye and died fairly quickly. Since then everything else has died as well, Mollies,cardinals,platties fig8 puffer clown loach and goramis. I only have 1 gorami and one glowlight barb left. On top of this i yesterday saw about 16 baby platties in the tank which seem to be thriving.
The water quality seems ok and i did get it checked by the local shop and they confirmed all looked well. The last couple of fish that died have got a cocoon around them. Any ideas

 

[Inchworm]

Hi menorcaman

Welcome to the forum. I'm sorry that you are joining us because of trouble with your aquarium.

We will need more information before anyone will be able to help you though. Please tell us as much as you can about the following:

The readings for ammonia, nitrites and nitrites, pH.

Water temperature

Amount and frequency of water changes.

It would also help us if you add your location to your profile because not all medicines are available in all places.

 

[Tempestuousfury]

to the forum. Introduce yourself in the newbie section.

Sorry about what happened. As soon as you get us the info we'll be abel to help you out.

 

[menorcaman]

hi
ph7.2
nitrate 20max
amm 0
im from lowestoft suffolk
tank temp 24
water change 20% every 10 days
external fluval filter
hope that helps