You don't need not to get RO. As long as you have some alkalinity substances in the aquarium, it should raise the pH a bit. Keep it stable. I don't think it matters (might disturb the pH a little bit) best to keep plecos between 7.0-8.0 alkalinity. slightly alkaline water. between 74 fahrenheit and 80 fahrenheit. CYCLE THE TANK OR YOUR FISH WILL DIE. I think you should see if your LFS will temporarily hold your fish for you while your tank is cycled. I'll bet they would for a small fee or free if they're really a good store (probably not. I've never actually tried to see if this is possible).