Arctic Pure | Best Defense

Arctic Pure Best Defense is a metal sequestrant and scale inhibitor for hot tubs and spas. It locks up dissolved metals (iron, copper, manganese) and excess calcium so they stay invisible in the water instead of staining your acrylic shell or scaling up your heater.

Why metals and minerals are a problem: Well water and softened tap water both carry dissolved minerals that don't bother you straight from the tap, but become visible the moment they hit a hot, agitated environment with sanitizer in it. Iron causes brown or rust-coloured stains on the acrylic and turns the water yellow when shocked. Copper turns the water green or blue-green and stains pillows and fittings. Calcium scales the heater element, salt cell, and any heated surface. Best Defense binds these minerals so they pass through the filter and stay in solution instead of dropping out as stains or scale.

When to use it: Add Best Defense every time you fill or top up the spa, especially if you're on well water or your municipal water has high iron. Also use it preventatively before shocking the water, before adding any pH adjuster, and any time you notice discolouration starting to form. Salt water spa owners running an Onzen or Spa Boy system should treat this as a non-optional part of every fill.

How to use it: With the jets running, add 1 capful per 1,500 litres (350 gallons) directly to the spa water at fill. For ongoing prevention, add a half dose every 4-6 weeks. If you're already seeing staining, dose at the full rate, run the jets for an hour, then test and rebalance the water.

Quick tips:

• Always add Best Defense before any sanitizer or pH adjuster touches the water — sequestering metals first prevents them from oxidizing
• If you have green or yellow water, Best Defense plus a filter clean and a shock dose usually clears it within 24 hours
• Sequestrants break down over time — that's why you re-dose every few weeks even if everything looks fine