Yesterday i made the switch from prime to safe. I have a 180 gallon aquarium so it just makes sense. Last night i did a 40% water change on all 3 tanks, using safe. This morning i wake up and every fish in my smallest tank is dead. The fish in the other 2 tanks look fine but it has me worried. They were just feeder fish i have had for like 3 weeks in the small tank. My other tanks are cichlids and tropical. I just want to make sure i didn't do anything wrong... I have done multiple water changes on that small tank in the past few weeks and even up to 50% with no fish loss. What do you guys think? Coincidence? I used a .1gram scoop of safe. Says that's good for roughly 25 gallons. Thoughts?