Do you have a liquid test kit?
You might want to check your nitrate concentration. Try to keep nitrate below 20ppm, but always aim for lower the better.
If it is high, it can easily cause algae boom. If 25% water change doesn't do the job, you should always increase the % water change. Double it to 50% or do it twice a week. Light exposure should be lowered as well.
Algae eaters will never be able to completely wipe out algae unless there is very little algae to begin with.
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