Yes you may use it with fish. However that being said, precautions must be taken to ensure the chemicals don't indirectly affect the fish. This can happen when you have a lot of algae in the aquarium that dies and starts to break down rapidly, which can cause rapid deterioration of water quality, in turn harming the fish. To prevent this, always do a cleaning of the aquarium prior to using algae chemicals. Try to remove as much of the algae as you can by hand. Flush out the algae with a partial water change. Don't take out too much water as this can remove too much of the good bacteria in the aquarim. so it is wise to never remove more than half of the water usually. If your aquarium is new you don't have much of this stabilizing bacteria so you don't want to use algae chemicals at all for about a month.
Another thing to remember is that using chemicals can lower oxygen in your aquarium temporarily. Make sure the filter is running (without the carbon in it) and it would be a good idea to drop an air stone from an air pump into the aquarium. If you see fish gasping at the surface for air that means they need more oxygen. Aquariums that are overstocked with fish are much more vulnerable to this problem. That is one reason it is so important to have a properly stocked aquarium.
If you have done a cleaning of the aquarium and have provided aeration, and your aquarium has been established for at least a month, then you should be fine using the Tetra algae control. It would be wise to also try to determing the root of the algae problem. It is always excess nutrients or excess light. Try to find out which of these problems or if both of these things are causing the algae, and then eliminate the problem.
answered 2 years, 11 months ago
12out of 12found this answer helpful.