First, any shape tank is ok. If you want a hex, buy it. Get whatever suits you. It is the surface area that matters. Bacteria grows on the surfaces of the substrate, decor, anything with vaying surface area. For example, tall tanks are good for reefs because they don't need large surface area for anerobic bacteria. Now, an aggresive fish only set up needs more surface area to break down all the extra waste.
Second, live sand and live rock is only necessary if you are going to do a reef tank. I would not recommend this for a beginner. Go fish only first to learn how to sustain them well. You could get reef fish, that way you can add corals, live rock, live sand, and invertebrates later on. But dead substrate is fine as long as you patiently wait for it to cycle. However, you can use live rock to cycle a tank if you don't want to risk losing fish. My point is, don't go spending all your money on live sand and live rock until it is time to do a reef. It is very expensive, and pointless for fish only... except that you can use live rock as a natural bio filter and beautiful decor.
Third, wrong again... large tanks ARE expensive. My Oceanic 200 setup was several thousand dollars. There are several thousand dollars put into it on top of that... live rock, sand, corals, fish. On top of that, there is about 2500 in equipment. So, large tanks are significantly more expensive than smaller ones. Use common sense on that one.
Now, the 80 gallon at Petstuff, Petsmart, whatever, isn't too expensive because the bottom glass is tempered. You cannot drill a tempered bottom, which is why it doesn't come with a sump. See, there is no overflow box in the corner for the water to flow into a sump. You can add a hang-on-the-back overflow box and sump, but it is rather pricy. Your best bet would be to buy a pre-drilled tank with an overflow box installed in the corner. Check ----. There are some great deals. And there is nothing wrong with a used tank as a beginner. But, for saltwater you really want a sump to accomadate filtration, skimmers, sterilizers, and other equipment.
But, yes, unfotunately the above post is correct on one thing.... the equipment costs add up quickly. Especially lighting. Once again, ----.
Let me keep going... my large tank is not messy. As a matter of fact, it is proven that large tanks are easier to clean and maintain than smaller ones. Also, there is a better chance of polluting the water in a macro-tank. Larger tanks have more water to dilute when you are messing around inside.
See, also, if something dies in a small tank... that's where you are screwed. In a large tank, like I said, something small dies, and you probably don't have to worry about it too much because there are sooooo many more gallons of water to contaminate. Now, in a reef, you have to watch the nitrates and ammonia if something dies. But, generally, you are ok unless it is a large fish. I have had a 9 inch lunare wrasse die in my tank, never to be seen again. The water remained perfect.
Now, if you can afford the larger tank.... go for it man. You will want to keep going larger anyway. It is addicting. I started with a 15. Now, you could always invest your money in a bigger, or better tank... and build the stand and canopy yourself. That's what I did in college.... and so did several of my friends that I turned on to aquariums. It is easy, and much cheaper. You have to keep in mind, pet stores really jack up the price on those things. Not so much the tank, but the stand and canopy. But, Home Depot or Lowe's has the materials cheap. Plus, it's fun to customize, trim, and build the tank.
As far as pumps, go mag drive. If rio's burn out, they have a tendency to release oil into the water, which will kill everything.
As far as heaters... marineland makes a good, easy heater. There are two temperature settings, both of which are good for marine tanks. It just makes it easy, so you don't have to adjust the temp. constantly. And the wattage depends if you are putting a small heater in the tank, and a larger one in the sump. It is all subjective. But, temperature is important.
There is NADA wrong with the petstuff, petsmart tank. If you don't want to go with the overflow box.... for convenience and lack of complexity, go with 2 emperor 400 filters on the back of the tank. Those things are the best hang on the back filters around. Later on you can learn about natural systems with a skimmer, even canister filters if you want to go that route.
Print this out and ask around man, you'll see the info is straight. Good luck with the tank. You're gonna enjoy it.
