I had read that before you put gravel into a tank you should rinse it with warm water until you get all the dust, etc. off. I bought a bag last night as I need about an inch more and the bag says to soak in COLD water....I rinsed the gravel in a bucket three times last night and left it soak over night in cold water. Is it bad to use hot water? or should I rinse again using hot water before I add it to the tank?