It's finally time to add some water to your aquarium, but don't fill the tank just yet. Pour in only enough water to fill two thirds of the tank, and use lukewarm water from the tap.
Don't use hot water, which can crack the glass. Cold water is no problem, but it can take quite a while for the aquarium heater to bring it to the correct temperature.
Another option is to use a high-quality kitchen thermometer and mix the hot and cold water until it reaches the desired temperature.
To avoid disturbing the aquascaping, the flow of water into the tank should be eased somehow. One method is to lay newspapers over the aquascaping, pour the water on the papers, and then remove them. You can also place a bowl or cup on the gravel and pour the water into that.
A third possibility is to place one of your hands palm up in the tank just above the gravel and pour the water onto your hand. You can also use one of the bulkier, more stable pieces of aquascaping -- a rock, for instance -- to break the flow of the water.
With the tank two-thirds full of water, the live or plastic plants can go in. Tall plants will look best in the back, and you can use them to hide the lift tubes, heater, air tubing, and other equipment. Smaller plants can go on the sides and near the front of the tank. Clustering plants around rockwork often creates a nice effect.
Do not mix species of plants so that they are scattered throughout the tank. In nature, plants of the same species grow in groups, and you want to duplicate this effect in the tank. Plants of the same species growing together are also often of different sizes, representing a mixture of young plants and mature plants.
The tank now has everything in it except the fish, and you can add the rest of the water. Add enough so that the waterline will be hidden by the hood. The water you're adding should be about the same temperature as the water already in the tank. After the tank is completely filled, you can begin turning on the equipment.
With all of the valves of the gang valve completely open, turn on the air pump. Air bubbles should be flowing from all air stones. Adjust the gang valve to even out the air flow. It is very important that the bubbles flow equally from all lift tubes, if you have more than one.
If the flow is greater in some tubes than in others, the undergravel filter may not work correctly because the tubes with the strongest flow can actually pull water down the tubes with the weakest flow.
Find the final steps to aquarium setup on the next page.