New Tank (for turtle)

Question
I've recently (and by recently I mean 2 days ago) bought a new aquarium tank and turtle. I have a small heater and the Fluval 2 Plus filter. Looking at the water today is like being in fog while you're driving, it's so cloudy. I was just wondering how normal this is and how to take care of my Red Eared Slider. I was told to feed him every other day and to clean out the tank once a month, but if the water is this cloudy now, I'm wondering if there's more to it...
Also, the water doesn't seem to be getting any warmer, is there any way I can check to make sur ethe heater is working?

Thank you for your time, I really appreciate it!

Answer
Alessandra,

With a turtle, I would recommend weekly 50% water changes.  They poop a lot and it needs to be removed.  Try doing a 50% water change today and see how it is tomorrow.  Also, is it a white cloud or a green cloud?  If you want to check the temp, by a thermometer, they are about 3 dollars at the pet store.