Sudden death of 4 platys 😩

[HVSBOO]

Good morning all looking for some advice..

Over the last week or so my tank kept going cloudy so I kept testing the water and doing small water changes every other day on the advice of my local fish store. Then this morning I found 4 dead fish in a panic I removed the remaining live fish and drained and cleaned the main tank.. now realising that was probably the completely wrong thing to do can anyone please advise on what I should do next? Pray for the fish that are still stuck with this newbie! Thanks in advance

 

[Colin_T]

Post pictures of the remaining fish.
How many fish do you have left and what species are they?

What are the tank dimensions (length x width x height)?
How long has the tank been set up for?

What was the ammonia, nitrite, nitrate and pH of the water before you drained and refilled the tank?

How often are you feeding the fish?

How often do you do water changes and how much do you change?
Do you gravel clean the substrate when you do a water change?
Do you dechlorinate the new water before adding it to the tank?

What sort of filter is on the tank?
How often and how do you clean the filter?

What colour was the water when it was cloudy?

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If the tank is newly set up (less than 2 months old) and the water was a milky cloudy colour, then it was a bacterial bloom that is normally caused by a new tank and a filter that isn't established. When this happens you get ammonia readings in the water. Ammonia is highly toxic to aquatic organisms and the best way to reduce the ammonia is with a big water change. Now I don't normally recommend doing a complete water change but if the ammonia levels are really high, then a complete water change has probably saved the remaining fish. Having said that, if the filter hasn't established, you need to keep the ammonia levels down until the filter has developed colonies of beneficial bacteria that convert ammonia into nitrite, and nitrite into nitrate. This normally takes around 4-6 weeks but can take longer.

To keep the ammonia and nitrite levels down, reduce feeding to 2-3 times a week and do a 75% water change 4-8 hours after feeding. You should also monitor the water for ammonia and nitrite and do a 75% water change any day you have a reading above 0ppm.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.