ALGAE TOT - FISH DEAD !!

Case 1) After the first dose of 10ml in a 110 gallon tank, which had been in operation for 2 months, were dead 24 hours approx 1/3 of all Guppies, mainly juveniles! The remaining fish hang around lazily, do not want to eat, etc.
Now I have 50% of the water changed, and I hope that to make ends meet!

Case 2) In another bowl, where the agent has been used well 1/2 year, are constantly died "throwing" very pregnant guppy females just before and there was no longer young. I was the Urache not clear, but I do because of the above case because now also a relationship.

Case 1) is in any case absolutely clear

I can only advise of the stuff, or is advisable to take it only for less sensitive fish.
Algae are killed reliably in itself, but it also has no fish.

The term "non-toxic for fish" is definitely a lie, the manufacturer would have to be forced to give a clear warning.