i would suggest getting Live Sand but since your saving money and what not, ill just leave you with this note on substrate, keep it clean lol. Crushed Coral isnt really the best for a SW tank. the lava rock will be fine, and as long as its porus enough it will populate with bacteria. i would invest a small amount of money on a couple small pieces of live rock. one piece goes in the tank to help populate the lava rock, and the other gets smashed and put in a filter bag in the filter. use carbon if you want, and some cheap, cheap filter floss. i say cheap because you will be changing it about every 5 days or so to prevent a build up of toxins. i would also find a source of RO/DI water just because this water is more stable and its easier on the fish. use a good salt mix as well as this will help stablize a few parameters. since coral is not in the picture yet i would not worry about lighting. i would however invest in getting a protein skimmer. skimmers remove a lot of the material from the water with micro bubbles and help keep the water clean as well. stick with about 10% waterchanges a week and you will be okay. and by okay i mean you will be a few steps closer to owning a tank full of healthy fish. be aware that the regal tang gets about a foot and may not last in that tank for long. the clowns will be fine in that tank, and you would also consider some peaceful wrasse species: six line, and radiant to name a few. any kind a goby will be acceptable as well.
For the first 3-4 months of the tank your focus is going to be getting some very hardy starter fish, gobies most likely and get the tank stable. add fish about 3 weeks into having the tank up and running. at this time you can also consider adding a small clean up crew to assist in keeping the tank clean. you will need to make sure they get a little bit of food as well. get the water changes started and make sure you get that live rock, it will help you out alot.
I cant stress enough to read as much as possible. books and forums like this are great to learn from others mistakes. knowing as much as you can about this hobby will be very beneficial for you in the long run. keep the questions comming.
