These Self-Watering Pot Reservoirs convert your favorite pots into self-watering planters, keeping your plants healthy and reducing the time you spend watering. Just place this self-contained adjustable reservoir in the bottom of your pot, insert the refill tube and cover with soil. The One-Gallon Conversion Kit holds four quarts and fits pots between 16" and 20" in diameter at the rim. The smaller One-Quart Conversion Kit holds one quart and fits pots up to 10-14" top diameter. Simply fill the reservoir with water through the convenient Fill Tube. The soil will be moistened through evaporative action from the reservoir below. May be used with a liquid or a water-soluble fertilizer. A vacation watering solution!