How long do you continue vacuuming your substrate after last ich parasite is seen? I continue my heat/salt treatment for an additional 2 weeks. I usually continue with vacuuming substrate too. Now that I have sand in the tank, I have lost quite a bit of it through all of the vacuuming. Should I continue it too for the final 2 weeks? It’s been 5 days with no (not saying the word) parasites. What do you guys think?