First of all, you need to determine how many chickens you want to keep and you have to build a chicken brooder accordingly because the size matters a lot in raising chickens.
Now, Take cardboard boxes which should be at least four and should also be large enough to accommodate chickens easily. Tape all four boxes in order to give them proper shape.
After that, you should turn this cardboard box upside down. Now take almost 24-inch long sticks which will be used as legs of this box and use drywall screws to fasten these sticks to the four corners of the box.
You need to make sure that the box should be at least 10 inches high from the ground. The sticks should be attached to the corners firmly.
After doing that, you should make a 6-inch hole in the upper side or roof of the cardboard box which will be used as a brooder lamp. This hole will also help in escaping from the excess of heat.
Now take a stick and attach the lamp to this stick with the help of a cord and insert it into the box through the 6-inch hole. Make sure you have attached the lamp with the stick firmly which will keep it in right position.
Brooder lamp should be hanged in the box and make sure it is half way of the depth of the box which is an appropriate position of it.
Now you should put the pool on a selected brooder location and spread a bag of chips and wood shavings in the pool. You can also use cinder blocks in order to provide proper heat to the chickens.
Then use a small wire outside the pool in order to keep the little chickens in the pool. It will restrict them from coming out of the pool.