I see you're new to the forum, so WELCOME

Just a few questions first: How long have you had your tank? How large is it? Are there any fish in it? If so, how many and what kinds? Also, do you have tests for ammonia, nitrite, and nitrate? If yes, what are your readings on these tests?
Cloudy water may have various origins, which is why I ask for tests results to make sure it is not a part of the cycling process. I assume you're aware of the nitrogen cycle. If not, please read:
http://www.fishlore.com/NitrogenCycle.htm, and then read the articles on this page:
http://www.fishlore.com/Beginners.htm .
What water conditioner do you have in mind? The one that removes chlorine from the water? If so, you add the dechlorinator to the water BEFORE you add the water to your tank. The water going into your tank cannot have any chlorine in it (nor any chloramine).
P.S. Cloudiness in itself should not be dangerous if it is not caused by ammonia, nitrite, or nitrate. You don't have to perform a water change in order for the cloudiness to go away - it should clear up on its own. Water can be clouded after a water change - it is normal. As for water changes in general - they should be performed on a regular basis to keep your tank water clean and healthy for your fish. The size and frequency of water changes depends on your fishload. A lot of people perform 15-30% weekly water changes, but as I have said, it's different for every individual. So tell us about your tank first so that we can know better how to help you.