My fish tank (a 10g) was setup 8 months ago with cycled water from another 30g freshwater tank. Initially, a couple of fish died, but none have for 4 or 5 months now, however, the water is very cloudy. I vacuum the gravel and clean my filter, and do plenty of water changes, but the cloudy water keeps coming back. I have tried an effective algae cleaner, but have come to the conclusion that it isn't algae. I have used seachem prime during water changes, and always condition the tap water. The Ph is neutral, though I don't have anything to check past that.
Any suggestions would be appreciated. Thanks.

How often are you cleaning and changing the water and to what volume ?
Also what type of filter are you using and are you giving it time to establish itself ?

My thoughts here are too much cleaning and not enough time to allow good bacteria to flourish and do their job effectively.

Ben is on the right track but I also have to ask how many and what kind of fish are you keeping in this tank?

Is the cloudiness whitish in color? Does it fade after water changes or at any other time at all? Is it really REALLY cloudy or just a little haziness? If you give the gravel a stir does the water get cloudier? Also as was mentioned earlier knowing what's in the tank would be helpful.

I would do a water change and then cut off feedings for a day or two and see if it begins to clear. If it does my guess would be the tank is overstocked and the filter can't keep up leading to either bacterial growth and/or lots of fine particulate.

solutions to common freshwater aquarium problems