Diatom growth sticks mainly to the surface of objects like the glass, live rock, and sand. I have never heard of free-floating diatoms which would cause cloudy water.... but that does not mean it is not possible.
Water changes are not going to get rid of diatoms in a cycling or new tank. You will just have to wait it out unfortunately. What you can do in the meantime is run carbon in your filters or put some reef-grade carbon in nylon stocking and float it.
After your tank is cycled you can add some mexican turbo snails and they will clean it up in no time.
ps- how much water do you have flowing through the system? You will need 10x for a fish only tank and 20-25x for a reef tank (multiply the number in front of the x time the volume of your tank, this should be flowing per hour). This will cut down the CO2 in the water, which leads to algae growth. Also, get yourself a phosphate test kit. Phosphate is probably the biggest cause of algae.
