Here's my situation, my betta (after nearly recovering from mild fin rot from when I got him) had a relapse. I put him in a 1tsp/gallon salt bath. On day 8 or 9 of the salt, his fins were beginning to grow back, but somehow, he'd managed to get ich while in the salt bath. I didn't even know that was possible. Anyway, since obviously salt won't work to kill it, I pulled out a box of Jungle Lifeguard I had from some other need in my 10g a year ago. It says it treats fin rot and ich. On day 10 of salt, I put him in clean water for 24 hours so as not to switch directly from salt to medication. The next day, I cut the tablet into 5 parts (the correct dosage for his 1g qt he was already in) and put it in after a 100% water change. So far, I think I'm ok.
Here's my issue. The box for the medication specifically says to do a 25% water change on day 6 (after a 5 day treatment). However, my betta is healing from fin damage in a 1g bowl, so 5 days of no water change would be pretty bad. How should I go about this? I assume doing my daily 100% water changes would dilute the medication 2-5x depending which day of treatment it is.