Are we wet yet?
Well, here we are. You have a room full of equipment, a head full of knowledge, a plan and probably a few more questions. So, where to begin? Well, the first step is not that exciting. Find an area where you can easily fill and empty your tank. I know this is not what you wanted to hear. This is a step you can skip, and many do, but I definitely would recommend doing this. In a perfect world we would expect to buy merchandise free of defects. However, as I'm sure you know the world is an imperfect place. So, to be sure your tank does not leak, fill it up. Let it sit for a while and check all the seams. This is one reason I had you buy the aquarium grade sealant. Like I said, you can skip this if you want, but can you imagine getting everything set up, and after all your hard work you find beads of water dripping from your tank? I've had it happen. Trust me, it's worth it to play the waiting game.
I think the best habit to have is, before you set up anything, seal everything that needs it. This includes running a fresh bead along the seams of your tank, your overflows, inside your sump and anywhere there is a bulkhead. Preventive maintenance is the best maintenance. Now in doing this you can conceivably fill your tank in a few hours, but it is best to let it cure for 12 to 24 hours. Again, this is up to you, but you have waited this long for a tank. Why not one more day?
If you choose to seal your tank this does not mean that you cannot continue to work. In fact, you can do absolutely everything except fill the tank up. If you are setting up a smaller tank, such as one with a self-contained filtration system, then the next bit does not really apply to you. However, most people will be utilizing a stand, tank and separate filtration system. So, I will explain process for the masses here.
First of all, get your stand in position. Do not place against a wall yet. Keep it a couple of feet away until you are finished. Now set your aquarium on the stand. Once you are satisfied, place the sump or canister filters inside the stand in the places you wish for them to exist. Be sure to keep in mind, you need room for storage of supplies and room for possible future upgrades. In the case of a sump, it is best to keep the "open" area of the top towards the middle of the stand. This allows you room to place external pumps or allows easy access to add additional filtration units to the sump itself. Just make sure you are able to still take the lid off of the bio-balls to change out the pre-filter pad during maintenance.
Ok, now you have your tank, stand and filter(s) in place. It's time to run the plumbing. This may or may not require another trip to the store. What you need is the tubing and corresponding connections to hook your overflows to the sump and be able to connect your return pump back to your tank. Now, most of the wet/dry filters will come with an inlet hose for connection to your overflow. This is typically a ribbed flex hose and I personally feel it creates too much noise as the water falls through it. I would use flexible clear vinyl tubing for both the in and return to the sump. Most local fish stores will carry this type of tubing, but I recommend checking the prices at a hardware store, such as Home Depot or Lowe's. You can usually find what you need there at a better price. Plus, these stores will also carry a variety of hose barbs. Those are the connecting parts needed for hooking a hose to your return pump or to your overflows. It is impossible to write a scenario for every filtration assembly. Every manufacturer includes different plumbing pieces with their units. It is up to you to determine what you need to complete your set up. There are many options when it comes to plumbing a tank, so you need to determine the scenario that best suits your needs. If your not sure, ask someone who knows basic plumbing to assist you. If you are using canister filters you more than likely will have everything you need included in with your filter. However, you may wish to have the filters further away from you tank than the hose allows. In this case you will be in the same situation.
The one aspect that I can touch on, which will apply to every tank, is the need to spread out the return flow into your tank. What this means is, if you have one return hose coming from your filter you should put a tee into it, diverting the water flow to two different areas of the tank as it returns. This will obviously aid in water circulation, which is essential to the health of your aquarium. The best scenario is to have a return on opposite sites of the tank, angled so that the water crisscrosses at the middle. This will assure that there is water movement traveling to both sides of the tanks, crossing in the middle and bouncing off the front glass. To improve on this even more, it is best to place a device that will alternate the water flow from one side of the aquarium to the other. The most popular choice is also very inexpensive. 3iQ Ventures as created a device called a SCWD, Switching Current Water Director. This goes in your return tubing in place of your tee. It is mechanical, non-electric, wave-maker. As the water passes through it, it alternates from one side to the other sending water through one return hose at time. The time intervals are related to the flow rate from your pump. The faster the flow, the quicker the alternation will be. All of the life you keep will benefit from this more natural motion within the tank. After all, picture how the water travels around the reefs. The current and waves approach the reef and shore, and then they recede the opposite direction. For now this should be sufficient for the current in your tank, but you will need to add additional current via internal pumps soon. So, keep that in mind.
Now you have everything connected hopefully. The overflows are running to your sump and your return is arranged to bring back the water to you tank. Now, check all of your connections, add wire straps around any hose connections to assure additional security and it is advisable to use hose clamps to secure any tubing to the back of your stand. At this point, you may want to mount a couple of surge protectors inside of your stand. Try to place them up towards the top and back of the stand. This will keep your plugs out of the way and is safer than having them on the ground in an area that they could get wet. Electricity and water is never a good combination, so use your best judgment in this area. Once that is completed it is time to slide the aquarium and stand into place. Obviously on larger systems you will probably need some assistance. There is no rule of thumb on how far the tank should be located away from the wall. However, you need to keep in mind the future possibilities of additional equipment and the need to do some maintenance if a problem should arise. So, find the line where it is still "workable", while remaining aesthetically pleasing.