Probably the chlorine. I doubt if chlorine is healthy for frogs.
If your talking about Swimming pool its because your pool has chlorine in it and chlorine kills fish :(
the chlorine in the pool was to strong for them
Well... if you were ODed with chlorine, you would die. The amount in a pool wouldn't harm you, but because bacteria and algae are 1000 times smaller than you, they can die easier. Yes, chlorine can kill.
Have you actually added liquid chlorine to the pool?
Free Chlorine is the Chlorine which is free to do its work in the pool, as opposed to Combined Chlorine which is chlorine that has combined with contaminants and is tied up and ineffective as a sanitizer in the pool. Sometimes you will see it abbreviated as FAC, which stands for Free Available Chlorine.
Thiosulfate will neutralize chlorine. Buy it at a pool store.
A Salt water pool is a chlorine pool. The difference is that in the case of a saltwater pool there is a chlorinater fited inline that converts the salt into chlorine automaticaly, Meaning that you don't have to purchace any chlorine to keep up chlorine levels.
You do not measure the Chlorine in a Baquacil pool because they are incompatible.
Bleach is unstabilized chlorine. It is just a weaker form of the chlorine you buy at the pool store.
opening a pool is different then closing a pool because opening the pool is when the pool is all filled up with water an fixed an has chlorine in it and closing the pool is if u don't have no chlorine in it and it is not fixed or don't have no water in it
Chlorine and stabiliser