Urgent help needed !!! 10 POINTS?

The nitrate level in my freshwater tank is extremely high and I have a few fish in there. Also, the water is hard. I have 2 african dwarf frogs, 1 platy, and 2 scissor tail rasboras. There is one live plant and driftwood. There is some dirt in the gravel. I do water changes. Oh, and for a bonus, Can somebody tell me how how to start the siphon for a gravel vac, I can't get it right. Is there some product that will make my tank water perfect? Thanks