Everything so often, your water quality will change. In the Midwest, for example, the water company will double the dose of chloramine in the Fall because fallen foliage produces algal explosions in the sewage system. Your best bet in the long run is to condition your water. Aeration for 24 hours addresses many, many issues. If you don't have water storage capabilities, I would suggest
1. do not do water changes then run off to work. Observe your fish for 5 minutes to see if they're stressed.
2. when you see stress, add another 2 - 3X dosage of your water conditioner. There's no toxicity and it often helps.
Having said that, I want to reemphasize that a long term approach is to precondition your water.
Good luck, Willie