So, the decision is made, you're going to keep tropical fishes. You've read all you can find about the hobby and you're all fired up ready to get started. You've been out and bought yourself that new aquarium, you've got it home and found a suitable location for it, and you're keen to get on and finish the job, can't wait to see it all set up.
Don't be tempted into putting any water into your aquarium yet!
Don't rush things, patience is a virtue in this hobby, it's better to take all day to set things up, than to dive in and rush things, only to find something wrong and have to start over again to make them right. Although in reality it will be more like half a day.
Follow these steps and you will find things easier in the long run.
If you have decided on an undergravel filtration system put the undergravel plates and uplift tubes in now. This is a pretty straight forward job, you may have to cut some of the plates to make them a fit your particular aquarium but there's nothing complicated there.
Gravel should be washed thoroughly before it goes into your aquarium (it'll be full of dust). Put a bit at a time in a bucket and run water through it from the tap or hosepipe, at the same time stirring and agitating the gravel, it takes some time to get all of the dust out of the gravel, so be patient, it's worth it if you don't want a cloudy mess when you put water into the aquarium. When clear water runs from the gravel then it's OK to place it in the aquarium.
In theory you should arrange the gravel so that it slopes from the rear of the aquarium to the front; this aids any debris to accumulate at the front of the aquarium when it's up and running, making it easier to clean. In reality, I find that the gravel doesn't stay that way; it will just find its own level. Either way you should aim for a depth of about two to three inches (5-8cm).
Set the aquarium heater to approximately 76F (25C) and place it on the rear glass of the aquarium at an angle of about 45 degrees, close to, but not touching the gravel. It should be placed near a filter outlet, or where there is water movement, so that heat can be distributed around the tank. Do not plug it in yet! Aquarium heaters must be submerged in water before being switched on, irreparable damage could be caused.
CAUTION an aquarium heater is hot enough to severely burn when switched on and not in water.
Powerheads can now be placed on top of the uplifts and secured to the aquarium with the brackets or suckers provided. Do not plug powerheads in yet! They need to be submerged, they are cooled and lubricated by the water, and running them dry could cause irreparable damage.
Internal filters can be placed at either side of the aquarium, or at the rear, simply insert the medium into the filter chamber and attach the filter to the glass with the brackets or suckers provided. As with powerheads, do not plug in yet!
If you've decided to use an external filter instead of the options above you can set it up now according to the manufacturer's instructions. The features of these filters may differ slightly between one and another and according to each manufacturer, although they all work basically the same, place the pickup strainer in the aquarium.
Place any air operated features (air stones, etc.) in the aquarium, and run the tubing out of the tank to the air pump. Unless you are using a check valve (non return valve) in the airline, it is important to have the air pump higher than your water level, water could siphon back down the line otherwise.
Rocks should be washed thoroughly and placed gently in the aquarium, don't over do it, this stuff is heavy, and to avoid the risk of it toppling you could consider bonding it together with aquarium sealant, remember to let the sealant dry before putting any water into the aquarium.
Bogwood and Mopani wood are quite attractive pieces of decor, (remember to soak the bogwood for at least a week prior to using it), try a little aquascaping by using the wood and/ or rockwork to form terraces rather than a flat expanse of gravel. This sort of decor can be beneficial in hiding the equipment you've put into the tank.
If you want to use artificial plants instead of live ones; they look quite natural and don't need regular pruning, you can now place these in the aquarium. Try to position your plants so that the taller ones are at the back and the shorter ones towards the front, this will create a pleasing effect and will help to hide equipment, as well as being a natural feature for your fishes.
You will have ended up with a number of plugs at the rear of your tank, use a multi-socket block to plug these into and be sure to keep the wiring tidy. But remember do not to plug any of the equipment into the power before you have put water into the aquarium.
So, now that you've thoroughly enjoyed yourself building your aquarium, the next job is to put the water in.