I have seen theese similar setups in a few shops here. I have never tried it before. It should come with a hydrometer if not purchase one to measure specific gravity/salinity. I would also start the research for care along with the gidence of the petstore. about. com has some good articles also this is a good one below

Here is a link that might be useful: reef central

I first got into reef tanks by buying a nano cube just like this. It worked great for awhile, the only problem was I didn't know enough to keep it looking so nice. Algae grew, things died, I was bummed. Since then I have done a ton of research and now I understand how everything works and wouldn't make many of the same mistakes twice. Oh yeah, I think I paid 350 for mine, but that was around 5 years ago.

You should check out http://www.nano-reef.com/ and http://www.reefcentral.com , both of those sites will be invaluable for their information.

Well it looks like the JBJ Nano cubes are basically an accident waiting to happen and the company does not render much in regards to fixing its problems......Nano-cube dot com is full of threads concerning issues with these cubes that just up and creack and JBJ says its all from shipping induced cracks where the glass is not properly treated and its substandard in regards to thickness is where ther problem lies....Even my LFS has since stopped selling them, as a few of the other LFS in neighboriing towns all due to breaking of the tanks on delivery, a week or a month or even 4 or 5 months later..........NANO VUBE bad!