I have had a mistking for a few months now and at first I was using filters water from my local petco to put in the mistking. About 2 months ago I decided to start just put regular water in it and just use reptisafe to make it good. Today I just saw a white powdery like substance on the side of my mesh cage and on my fake plants. I think it might be like a calcium build up because the reptisafe says it adds calcium to the water. Should I be using filters water from petco?