Building your own reptile terrarium can be a fun and rewarding experience. The first thing you're going to have to do is decide on a reptile, if you don't already have one. It is important to understand your pet's needs. Mainly space, humidity, light and temperature requirements. Once you know all of this use this information to design your cage.
The easiest way is to start with an aquarium of the appropriate size, then ad a suitable substrate; coconut bark for a tropical animal, calcium sand for a desert, ect. After that find something he or she will like to hide under such as a half a log, some rocks or sticks. If you collect these from outside make sure to soak them in bleach. On top of the hide structure I put something to climb on, usually more rocks or sticks. Above these is where I put the lighting.
I use a basking light for heat and a fluorescent light to provide UVB. Putting all of this on one side allows space on the other side to place food and water, and also allows the reptile to thermal regulate by having different temps. in different parts of the cage. Depending on how cold it gets in the room at night a heat rock or tape can be used to add heat. Having all of this on a timer is an easy way to control your pets photo period.
To increase humidity if necessary a fogger will work. Having a jar of water with an aquarium heater and bubbler in a back corner where your pet can't get to it will also work. Desert animals usually do fine because houses are usually dry enough.
Once you've got all of the basics taken care of then you can add some scenery. Some plastic plants, more rocks, sticks or some fake vines. These will ad aesthetics as well as make your reptile feel more in his or her natural habitat.
