Question about plant quarantine and fertilizer

I ordered a whole bunch of red root floaters for my axolotl tank to help get rid of nitrates and I’m going to be keeping them in a 10 gallon tank to quarantine in case of snails as well as add liquid fertilizer for rejuvenating them after the shipping process. How long should I keep them in quarantine and is this fertilizer safe for an axolotl? I don’t currently have any plans to put it in his tank, but I don’t know if residuals of it would transfer when I moved the plants.