Thanks for the answers
I'm glad to hear this since I prefer to keep one HOB. When I turned it off for a few hours yesterday my fish seemed bored. Who knows, but they just didn't swim around much. I'll sit tight on more changes until I get co2 testing items. I've been monitoring pH and the fish in general adjusting the water slowly. I have been all fish, too except for a failed attempt at keeping plants growing a few years ago. This is a nice, active forum.