I know I only want 2 or 3 archer fish. I have a 65 gallon tank. I plan on filling it to 50-ish gallons to leave some room for jumping/spitting. I know how to get the SG to where I want it. But my LFS said something about "needing" crushed coral at the bottom for buffering or something. Do I "need" a substrate? What other water parameters do I need to be worried about with archers? More questions to come, but my little one just started crying..... can't ever get anything done, lol.