Hey Everyone! I have been reading through threads for weeks now as I preped to start my 36g fish only tank! I have never had an aquarium and was told to start with freshwaster because salt is too hard.... I said BRING IT. So here i am understanding why they say its diffuclt but well worth it.. I have a question about he oxygen in my tank. I have a 36g tank with 40 pounds of live sand 35-40 pounds of life rock heater a single blower Reaction 4-stage Canister Filter with UV After my water tested that the cycling had completed, I added two Damsel fishes. They are doing really well, they are eating and swimming around. I am concerned that they may be breathing heavily and from what i understand it may be due to low oxgyen levels in the tank? If so, would adding a bubble ring be helpful? Please be kind, I am just starting out and need advice.