GrowMax Water Filtration System Pro Grow 2000 (treats 25k gal.)The GrowMax Water Pro Grow 2000 Professional Garden Water Filtration System filters up to 25,000 gallons of water. GrowMax Water Filtration Systems increase the effectiveness of your nutrients and fertilizers helping you grow healthier, higher yielding plants, flowers, gardens, fruits, and vegetables. Adding a GMW Filtration System to your garden will help strengthen plant roots and protect your soils beneficial bacteria. Simple set up and maintenance