Hi,

1. 500ml

2. 1-3ml reagent used per test, how long a bottle may last will depend on tests/per day and actual KH value. A 500ml bottle may last up to 3 months if testing 2x/day at a value of 8dkH

3. Possibly, but not recommended for accuracy and warranty purposes

4. Technically there is no shelf life. What matters most is that the bottles are kept closed and away from direct light when not in-use

5. Unlikely. We offer ready-to-use reagent to eliminate the hassle of mixing one's own batches.

6. It should be kept away from direct light and in a temperature stable environment