Water Tight Systems MT-10 Metal Trap - Pre-Filters Water Up To 10000 Gallon Pre-filters up to 10&#44; 000 gallons. Pre-Filters Stain-Causing Metals Before Having a Chance to Damage Your Pool or Spa. Traps Iron and Copper from Municipal and Well-Water Sources During Fills and Top Offs. Incorporates New&#34;Filtration Media Materials&#34; to Trap Metals. Easy to Use&#33; Just Attach to Hose&#44; Flush and Start Filling.