Hi everyone! I am getting back into the aquarium hobby after months of bad depression, and I really want to set up a 10 gallon black water tank. I am far from decided on exactly what I will be keeping it (dwarf cichlids? licorice gouramies? unusual tetras? so many options...), but I wanted some advice on how to reduce the PH of a blackwater tank. In the past, when I had my licorice gouramies, I would use a very dilute mixture of 1/8th tsp pure sodium bisulfate in about a cup of distilled water, and used a few milliliters of this mixture per gallon of distilled water to get a PH in the low to mid 4's. Is this actually safe for fish? If not, how else can I lower the PH without playing with substances that can severely burn me? Thanks 