Last night before starting this thread I drained the tank and removed the gravel, and when the tank dried you could see the white film left behind, and at the gravel line it actually left a ridge, I also noticed my 2 blue buckets used for fish tanks only are now stained white at the bottoms. I tried warm water, vinegar and water and strait vinegar to remove the film but it only smears, I also tried a dry paper towel, that seemed to work best, but not to satisfaction.
So next question : Has anyone tried rubbing alcohol, it would absorb most chemicals and still mix with water to make rinsing easier.
PS : Last night I purchased the API Master Kit.