The main ingredient is probably concentrated sodium thiosulfate.
I know this may sound crazy, but if its a liquid a drop or two will do. And in either case 1, 2, or 3 drops will do no harm, you can't really over dose at that tiny amount
But to be sure fill your bucket with tap water use a swimming pool test strip to test for the average residual of chlorine/chloramine in your tap water.
Then add a drop of API conditioner and in a few moments use another of that same type swimming pool test strip to see if its been neutralized. If not, try another bucket or tap water and test with two drops.
These strips can be purchased at most big box home improvement store that sell swimming pool accessories, (Home Depot, Menards, Lowes, in the US, or B and Q in the UK, or Do It Center in Central and South America.
On the test strip above, Chloramine is listed, as Total Chlorine