/diy/ - Do It Yourself

I'm trying to build an aquarium for the first time and am confused on the bacteria and and all the living accessories I need to keep a healthy tank.

I see a lot of people using ADA products in their substrate to promote beneficial bacteria, but it is really expensive.

I want to do a bit of an aquascape with living plants, rocks, and a small amount of fish, shrimp, and snails. Could I get some recommendations on what I should be looking at for nutrients and bacteria?

Also, if I have a bunch of living plants, do I need a filter and pump set up? I'm getting mixed information on whether or not the plants will create all the oxygen the fish will need or not. Does it depend on how many plants are in the tank? If so, how do I know if I have enough plants?

Starting with a 20 gallon tank if this makes a difference.