Keep on reading
. You never mentioned your lighting. Remember, light drives everything. IMO, if you got medium-high light, you gonna want CO2. EI really is not necessary in low light tanks if you have a decent bioload. Otherwise, you might want to dose leaner.
Agreed. From what I have read that is. I'm in the same place as you now: learning. but I have been advised by so many that you have to get your CO2 right or you run into a lot of problems, mainly algae.
Might want to check your KH and GH of the water. 7.6 is barely "high". You might need to cut with RO if the GH/KH are really high.
I was going to comment similar in that 7.6 is not 'unsafe' depending on your stock. my tap water is the same pH as yours. but it is also very soft, almost no hardness GH or KH. Maybe you can match your stock to your water instead of the other way.