spiketooth
Aquarium Advice FINatic
This is especially true with ich which lives in substrate for a few weeks.
Ick is a parasite which mean it needs a host to live, normal strain ick(have not read any artical were someone was dealing with a different strain) only lives 2-4 days without a host. Not a few weeks. Different plants absorb different amount of ammo and nitrate. Its true plants are not the fix for nitrate but it helps just need the right plants. Also stocking, left over food also can contribute to access nitrates with in a tank.
If you get your plants from a tank with just plants in it, i would not worry to much. Might get some snails