I apologize in advance for the long post. Purchased 200 Cardinal Tetras from a wholesaler through a LFS for my 180. So LFS picked them up from the airport, and I took them straight from them. Got them home, 2 bags which seemed like a lot for 200 fish and they were TIIINY. Opened the bag and tested the water. Ammonia was 0 the PH was 8.4 which was surprising. My PH is 7.4 so I was concerned that would be a shock for them. I put them all in a bucket and added 1 cup of water from my quarantine tanks ever 15 minutes, over about 45 minutes (I dont normally take that long but I was really worried about the ph difference) I tested the Ammonia every 5 minutes and it was always 0. Got them into my quarantine tank (with established filter and air, temp at 80 and 1 tbsp salt per 3 gallon as I can not get meds in Canada) they seemed to settle. Next morning 90% were dead. Checked the water parameters temp was 80 ph 7.4 ammonia nitrates nitrites all 0. What did I do wrong?? I did not feed them, was it PH shock? Im pretty choked. Ive been keeping fish for a long time, have a very established 180 (3 years old), heavily planted. Have never had any issues quarantining fish before. Bad batch maybe?