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Water changes and bacterial blooms


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Hello everyone,


I was curious on how you guys change water in your larger tanks. I notice that sometimes after a water change, my water gets slightly cloudy for a day or two with what appears to be a bacteria bloom. 

Currently I drain about a 1/4 or 1/3 of the water, add API stress coat water conditioner to the tank (I dose the amount for the whole tank 125g), then add the water using a python from the sink. 

Is it normal to get a slight bacterial bloom after a water change? Should I be doing something different? Fish all seem to be fine, ammonia and nitrite are 0 when this happens. 


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That isn't normal in my experience. Are you doing other maintenance like gravel vaccing or cleaning your filter? 

Typically I will only see a bloom from disturbing too much bacteria at once. For example if I did a bigger than normal water change and cleaned my filter at the same time. I don't use stresscoat but I do use API dechlorinater so maybe that's the issue. I did a quick google search and it looks like there are a lot of people that have asked if stress coat causes cloudy water.

If your fish aren't acting differently I wouldn't worry too much. Maybe try a different dechlorinater if the cloudiness bothers you.

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