All three pools were freshwater and heated! (edit- Make that four pools, I forgot the teen-only pool -end edit) The Aquaduck is also freshwater, but not heated that I could tell... I hear most other cruise-lines use seawater. I don't know if that's true or not.
There's also a couple of infinity hot-tubs that hang over the side of the ship and have a plexiglass window in the bottom so you can see down through it. I have some pictures of those somewhere too.
I was up at 5am every morning. Doesn't matter what time I go to sleep, that's when I get up. So while the rest of the ship was dead asleep, I had the whole ship to myself, well, if you don't count the Captain who was also wandering around the ship at that time.
That's the only public pool I've never had a problem getting into. I didn't need my test kit, it was perfect! Well, I'd had issues around 1 or 2 in the afternoon when the family pools had a bazillion kids in it. LOL
It's amazing the amount of cleaning they do on that ship when everyone's asleep! I'll hunt down the other pictures I took of the other water features on board and post 'em later.
If you're thinking of taking a cruise, I'd highly recommend Disney. Even if you don't have kids! There's adult only sections where you'll never even see a kid. Nobody does it like Disney. (Oh, but it costs WAY more than anybody else. Totally worth it though.) We compare our pictures and videos with my in-laws pictures and videos from their carnival cruises and have decided the cruises they go on are for old decrepit people.

Looks totally boring...
Ohhh! Wait, I have a site somewhere... Found it!
http://disneyship.shutterfly.com These are all the pictures I took from our vacation if you're bored.