Plastic buckets trap moisture a can really cause you lots of problems. I don't think that is your immediate issue though, are you using a ph meter? When your ph is off it will lead to a ton of problems. You can get a ph meter for around 30 bucks and it will make your growing go a lot smoothly. In the future you should look into cloth pots!
So it looks like a calcium consumer with one of your plants but it would help to know what you are giving the plants in terms of calcium. If you aren't giving them anything yet then I think you need to and the problem with the spots should stop. Could be a water issue or pH but most likely its just ran out of calcium to eat so its eating its leaves.
those pail are the worst for growing!!
only use those if you know what your doing..
transplant to 10 gallon fabric bag and you may have a chance of them recovering..
Plastic buckets trap moisture a can really cause you lots of problems. I don't think that is your immediate issue though, are you using a ph meter? When your ph is off it will lead to a ton of problems. You can get a ph meter for around 30 bucks and it will make your growing go a lot smoothly. In the future you should look into cloth pots!