A Trichlor tablet is most common among pool owners. It comes in a package of six and can cost $4-10, depending on the size of your pool. They are often found in a blister pack or a sealed container that must be pierced with a blade. In some cases, you may find trichlor tablets in smaller containers as they may not be used for long periods. However, pool owners should have an ample amount of these tablets on hand because they come in handy when there is no time for running out to the store for more granules or powder.