Hydro Pure Metal Trap MTR10 Pre-Filters Water up to 10,000 Gallons MT-10 MTR10 pre-filters up to 10, 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 "Filtration Media Materials" to Trap Metals. Easy to Use! Just Attach to Hose, Flush and Start Filling.