King Technology FROG Filter Mate Mineral Hot Tub Sanitizer for Filter Cartridges, Up to 600 Gallons, 01-14-3712

The King Technology FROG Filter Mate, order code 01-14-3712, is a mineral sanitizer for hot tubs up to 600 gallons that sits inside the filter cartridge core. It lasts 4 months and works together with a low level of bromine or chlorine.

How it works

Water moving through the filter enters the unit through openings in its cap and sides, picks up a small dose of minerals, and carries them back into the tub. King Technology says this lets you cut bromine or chlorine use by up to 50 percent. The minerals do not replace sanitizer, though: keep at least 1.0 ppm of bromine or chlorine at all times.

Where it goes

In most hot tubs it slides into the center of the filter cartridge, and the rod can be cut at the hash marks if it is too tall. It should not sit so low that it blocks flow. On skimmer filters with a 2.5 HP or larger pump, place it in the filter well beside the cartridge, and on tubs with small cartridges, set it in the skimmer tray.

Before you install

Balance the water first: pH 7.2 to 7.8, total alkalinity 80 to 120 ppm and hardness 150 to 250 ppm. Set the reminder dial 4 months out, and replace the Filter Mate then or whenever you drain and refill, even if media still seems to be left inside. It is not refillable. The same item is also sold as the Spa Frog Mineral Purifier.