Cyling new tank

I thought I would make a post under goldfish maintenance, because the fish are doing great after being poisoned by ammonia. I was making some pretty big mistakes with my fish by cleaning the entire tank instead of doing water changes. This either kept the cycle from forming or broke it. The fish were poisoned. It was time to get a decent size tank for them, so now they’re living like rock stars in a 40 gallon and loving every minute of it. I also added a pond pump. Will add a second once its cycled, but right now its in the cycling bucket

Every day I’m removing about 20% of the tank water with a gravel vac and putting it in the bucket with the cycling pump. This is keeping ammonia levels low in the fish tank. So far they’ve reached .5 ppm, but the cycling bucket is closer to 5.ppm. My question is, should I start testing for nitrites yet? I haven’t been using water treatment in the cycling bucket. I hope this is right, but what would be the need. I’m using the single dose Venus recommended in the fish tank with every water change

One of the fish has a lot of black on the fins, top and tail, but the other one seems to have made it through without being hurt. I’ve just finished the second round of aloe remedy which seems to have helped. At least they seem to be happy and eating a lot of food. I’m curious as to how long before the burn marks fade or will they be there forever? Guess it doesn’t matter because they blend well. If you didn’t know the fish, you wouldn’t know it had been burned

Thanks again for all the help