Well, sorry if I've missed some other thread of your story but it sounds like you've got some nice equipment and access to gravel from your other tank and other good things, but its just that you are maybe your goals and execution order are a bit off. You need to fishless cycle this new tank I'd think and we need to get the sequence straightned out.
First, you need to have a good test kit and already know how to use it ideally about the same time you start up with water. Also you need to have found the right type of pure household ammonia and that can sometimes be a bit hard to find. The reason you need these in hand is that your idea (I think!) of moving over some mature gravel, while good, lacks any food (ammonia) to keep this small colony of "seeding" bacteria in the gravel alive! Because gravel bacteria are not inside a filter with a flow of food (ammonia) and oxygen (water flow), there will not be very many of the beneficial bacteria.. but there would be enough to be a good small beginning seed for a fishless cycle with pure ammonia, I would think. Are you planning to use some mature media from your old filter (I may have missed this in another thread?)
The cloudiness (either because you disturbed old gravel by moving it, or because you're getting a bacterial bloom from the new availability of stirred up bacterial food) is not of any importance or significance to you. Assuming its a bacterial bloom, its simply the heterotrophic (the bacteria that convert organic materials into ammonia, not the beneficial bacteria we want) bacteria having a feast. The fish food you've added will simply add to that and make the process more confusing. Attempting to cycle with fish food is only recommended in unusual cases where people simply can't get their hands on household ammonia and is more or less a last-ditch method. Its so much easier to get an understandable result with pure ammonia!
Anyway, I may be way off base for your situation(!), but if not, hope this helps some. Clearly, getting a good liquid-reagent based test kit is a first step before you can know anything about what's going on.
~~waterdrop~~