I am setting up a 5 gallon tank for my daughter's betta fish. Right now it has two plants in it, and some bright pink and blue gravel that I might replace with Bio Complete. There is no betta yet.
(I am using an old filter and old gravel, so I am hoping that there are plenty of good bacteria already established, but I will absolutely test the water before introducing the fishy).
I have read that, in heavily planted, lightly stocked aquariums, you can successfully change the water only a few times a year. If any of you have successfully done this, I would love your advice.