Help choosing a substrate
I am in the process of setting up a 125g Fancy Goldfish tank. I want to use dark slate colored river stones between .5-2" and some larger ones for my hardscape. I am trying to locate a cheap enough substrate to have about 2" of gravel in my tank. Would I be better to do 2" of river stones/pebbles or should I get a base layer of something like color quartz or flourite and top that with a layer of the pebbles? I'm looking for something that is cheap but that will not jack the pH up to 8 or leach off poisons into the water.