I used the Tetra Algae Control and it has killed most of my fish.

So I picked up tetra algae control and it killed 7 of my fish within a day of purchase
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Another chemical alternative to hair algae is PondCare "AlgaeFix" or Tetra "Algae Control". Both are the same chemical. This will definitley kill you hair algae and give very fast control. So be sure to remove most of the algae first by hand so that you don't kill off a a big mass of algae all at once. It is better to use this product as a preventive treatment before you have a lot of hair algae. You will have to dose at least 3 times for the first week and every week after that. We don't recommend this product to kill green water. If you use it to kill green water you likely have dead fish due to the low oxygen levels that will occur due to the decomposing dead algae. Use a clarifier flocculat first for green water and then use the AlgaeFix or Algae Control to prevent it from growing back.
Tetra algae control almost killed 3 cory catfish
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Following the directions provided on the $3 bottle of Tetra algae control I felt there was some risk due to some reviews I saw online saying folks killed their fish off using it. Well IMO these folks must have dosed the hell out of the tank. I highly doubt they used this product as directed... Why do I say that? I have discus, angles, and neon tetras in the tank that was treated. They never even looked as if they were in any stress what so ever and days later with clear water are thriving, feeding and doing what fish do.. Tetra Algae Control killing my fish over and over again
Photo provided by FlickrI used some of Tetra's Algae Control -- probably too much, like +1 or +2 extra mL
Photo provided by FlickrMy fish all died off within a couple of hours
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