Cycling 20gal freshwater tank

Never heard of atm colony. There are more than a few rebranded products of the same origin out there along with a bunch of bogus products. If you are in need of a seeding product for fishless cycling, stick with what's proven working. Tetra Safestart is one of the proven working products for cycling a fish tank.

You don't have to add 4~5ppm of ammonia twice a day. Once a day is enough. By adding ammonia twice a day, you are creating a lot of nitrite.

It can be as few as a few days to as long as a few weeks before you see nitrite start dropping.