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My fish tank has algae. Is it safe to clean the water and filter?

Updated On September 23rd, 2025

Pet's info: Fish | Betta | Male | unneutered | 8 months and 29 days old

Is it safe to change my fish’s water and filter? The algae got in up in the filter and in the water.

1 Answer

Most Helpful Answer

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Answered By Angel Alvarado, LVT

Licensed Veterinary Technician

Published on April 19th, 2019

Yes, you can rinse filter media (the sponge) using tank water. This will preserve beneficial bacterial populations in the sponge. The plastic filter parts can be rinsed and scrubbed using tap water. Perform a partial water change, no more than 30% total volume, using conditioned water that is temperature matched. To limit algae overgrowth, do not overfeed, limit lighting to 8-10 hours daily and monitor water temp. If possible, turn up filter flow to get the water moving. Algae thrives in slow moving water. Do this only if your fish are not affected by stronger currents.

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