Ignore the "not changing the water" person. If you have an infection, you want to keep the water clean to prevent further damage (and poor water quality is a contributing factor and cause of a lot of infections like shell rot). The "not too clean" person may have some truthfulness to their words... too much of a water change on open wounds may be detrimental. I'm not sure, but as a general passing thought, you're putting back uncycled water into the tank... there's generally copper (most water systems in housing are copper, usually as it's going into the house) in the water and then whatever chemicals your location treats the water with. And open wounds and infections may cause a weakened state in which too much "new water" from water changing may be bad. However, I've never actually looked into that so that idle thought is probably very capable of being successfully shot down (and I don't mind if it is lol).
Generally, I do a 50% water change every week or every other week on all my tanks, irrespective of the issues or non-issues going on. And I tend to pay more attention to the tanks that have anything I'm treating in them, but that usually just means more filter changes, more substrate vacuuming, etc not really more water changes since I'm doing that regularly enough already.
Anyway, keep talking to people and gathering info... but in the end, do what you think is best. Based on the information you've been provided, sometimes it really boils down to different things work for different people. (However, I can't imagine not changing the water EVER being a working thing but I guess with the right kind of filtration and maintenance you could. But eww, that's just... ew lol)
Generally, I do a 50% water change every week or every other week on all my tanks, irrespective of the issues or non-issues going on. And I tend to pay more attention to the tanks that have anything I'm treating in them, but that usually just means more filter changes, more substrate vacuuming, etc not really more water changes since I'm doing that regularly enough already.
Anyway, keep talking to people and gathering info... but in the end, do what you think is best. Based on the information you've been provided, sometimes it really boils down to different things work for different people. (However, I can't imagine not changing the water EVER being a working thing but I guess with the right kind of filtration and maintenance you could. But eww, that's just... ew lol)
