Do a 90% water change and gravel clean the substrate before raising the temperature. This will reduce the number of disease organisms in the tank and give the heat a chance to work.
Make sure any new water is free of chlorine/ chloramine before it's added to the tank.
Clean the filter too. Wash filter media/ materials in a bucket of tank water and re-use the media. Tip the bucket of dirty water on the garden/ lawn.
Then raise the temperature to 30C (86F) and keep it there for 2 weeks. After that you can reduce the temperature to 24-26C, depending on what you are keeping.
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The following link has information about white spot and different ways to treat it. The first post on page 1 and second post on page 2 are worth a read.
This is a common question that is often asked, what is ich and how is it recognisable and what causes it? The real term is ICHTHYOPHTHIRIASIS. OR commonly known as white spot. It is an extremely comon parasite that affects aquarium fish. It is highly infectious and potentially lethal and...
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