OK I am going to start to use Kalk, my question is how much can I mix at a time. My tank evaporates around 1/2 gallon a day, can I mix up 2 gallons and let it sit in a coverted rubber maid container (I assume i can store in a rubber maid container)? Also is it ok to leave a very small pump in the kalk mix. I know I need to mix the kalk and then draing and use just the liqued but I wasnt sure how long it could sit and can you strore it in a rubbermaind container Thanks