Hi, new here and looking for help.I recently bought a 75 gal. fresh tank. marine land 360 canister, marine land 300w heater. I am doing a fish in cycle. I was told by my Lfs 12 fish is just right for that size to cycle. I got 12 tiger barbs. I also told them in the end I wanted 2 schools of fish (tigers and cardinal tetras) and 5 discus. ya now I know now that's not gonna happen. they told me as long as I kept them in schools I would be fine. salesman, gotta love em. anyway I have 12 tigers that we love. very cool fish. now I am going to do a species tank of all tigers. its been 2 weeks since I set up and over a week for the fish. my levels have been zero's, including ammonia of course. I did a 8 gal water change 2 days ago and today I put in tetra safe start plus. once I get cycled when do I add more tigers? how many at a time do I add and how many is too many for 75 gal? I was hoping to get around 50. I am worried about bio load with that many going in. will my bacteria be able to handle that load or will I be fighting levels for awhile? sorry this is long winded but I want to get it right and my Lfs apparently doest know or care.