Preventative treatment for new fish

Hi all.

I'm in my way to buy new fish for my established 5ft planted aquarium. Currently have guppies, platties, rasborahs, tetras, shrimps.

Any tips on preventing introducing disease? Obviously I'll be quarentining them.

How dies the potassium permanganate dip work?

Also, any suggestions what fish will work?

Thanks in advance ☺

 

2 weeks observation normally good enough to see if any disease pops up. Paraguard might be a good prophylactic in qt, as it is quite mild, can even dose with shrimp. Else peroxide dips work for me, 5ml/liter of 3%/12vol for 30 minutes before going into qt.