Keep the ammonia down!! Defiantly stay with the bigger water changes cause that's the only way to fight it off. After a few day's don't give up because it takes some work!
Yes, a fish-in cycle can take weeks and requires patience and diligence.
If you know someone with healthy tanks, and can get them to give you either a piece of filter media from their tank, or even some squeezings from their filter media/sponge, you can put that in your filter to seed your tank with the needed bb. (beneficial bacteria) This will help jump-start the bacterial colony you need in your tank.
The key word here is HEALTHY. You don't want to get it from someone unless you know they have no disease or parasites in their tank.
I did a fish-in cycle with Stability from SeaChem in a 30G...
The only fish I lost came from a source that sells terrible stock anyway... Make daily WC of 10-25% and test daily... keep watching for spikes and be ready to make multiple WC's in order to keep the fish happy.
Have been testing daily and doing water changes as the ammonia rises. It is hard finding a tank for a donor, as the lsp is Petsmart.I am not giving up, this tank is going to make it sooner or later.
Nitrates up to 40 is considered ok for most hardy fish in most people's books. More sensitive fish might do better in 20 or below range, but nitrate is MUCH less toxic than ammonia or nitrite. Those levels look great