Tooned outs 55g Tank

[tooned out]

I've had several fresh water tanks over the years but I have never owned a salt water setup.
I spent many hours reading the forums and trying to learn some of the inns and outs of Reef tanks ect... Thanks to everyone who posts questions and answers on here they are very helpful. Soooo here we go...
I made a trade for this tank for stuff that was sitting around my garage so I felt that even if I didn't enjoy the hobby I wasn't making such a big investment. It came as a pretty complete setup that the guy had stopped using about a year and half ago and put it in his garage. Here is a list of what came with it.

55g glass tank
custom cherry wood stand and top
10 or 20 (i can't recall what he said it was) Acrylic sump tank.
MRC OF-100 protien skimmer
RO/DI unit
Mag drive pump
MH light
2 power heads (that don't seem to be working)
about 30lbs or so of dryed out rock (was live rock at one time )
the tank still had 2 inches of sand in the bottom that was from the previous set up.
heater
Refractometer
chemicals
a dual dosing system that he said he couldn't figure out how to use.
and a bunch of other misc stuff...

So far does that look like I have pretty much everything for a good starter set up???

I have hooked it all up using tap water just to make sure I didn't have any leaks or anything everything seems to run well as far as the pump and skimmer go and water circulates well through the system.. I need to replace the 2 power heads (they are Hydor Koralia) I have soaked them in vinegar but I don't see anywhere to open them up to clean them out or anything.

Next I have to hook up the RO unit and make some salt water for the tank.

The Rock has been stored in tight lidded buckets that still have some water inside them. The guy I got the tank from said the sand and rock should be more than enough to get the tank cycling.. so my question is..

1) should I clean the rock and sand with a water/vinegar solution prior to use or just go for it?

2) Is 2" of sand a good depth for a sand bed?

 

[tooned out]

here are a couple pics of what it looked like when I picked it up in the guys garage.

 

[RockStacker]

It looks like you have most of the equipment covered.
I'm sure you will end up needing some other stuff here and there, but you have most of what you need to get the tank wet.

I would give the rocks a good rinse in RO/DI water. Chances are, there are already a lot of dead matter in the rocks so clean it within reason.
Anything else not washed away would contribute to the ammonia which would help start off the nitrogen cycle.

I would ditch the old sand and get new ones. Trying to reuse old sand usually ends up being more trouble than it is worth.

For the Koralia pumps, the only things that come off are the front cover (squeeze the two clips on the sides) and impeller-shaft assembly. The back-end housing is sealed and is not usually user-serviceable.
If the Koralias are not working, there are several possible causes:
1. Calcium/lime buildup in the impeller shaft has caused the shaft to seize up.
2. The impeller magnets are busted - water seeped into the magnet casing and caused the magnet assembly to swell. This will prevent the shaft from rotating. If this is the case, you can buy replacement parts for the impeller-shaft at several online vendors.
3. The electrical components in the back-end housing is busted. I would not attempt to use the pump if that part is broken.