BioGuard Arctic Blue Shock is the first step in winterizing a pool — a quick-dissolving granular treatment that oxidizes, clarifies, and buffers in one application, so the water going under the cover is as clean as you can make it.
Closing a pool well is entirely about what you leave in the water. A closed pool sits for five or six months with no circulation, no testing, and no corrections. Whatever organic load is present in October has all winter to break down, feed algae, and consume whatever sanitizer remains. That’s why some pools come up clear in April and others come up as a recovery project — and the difference is almost always what happened at closing.
Arctic Blue Shock addresses that directly. It oxidizes the organic waste accumulated over the swim season — body oils, sunscreen, cosmetics, nitrogen compounds — so it isn’t sitting in the water all winter. It clarifies, pulling fine suspended material into the filter before shutdown. And it buffers, moderating the water’s chemistry heading into a long idle period.
The practical benefits show up at opening: less algae, lower chlorine demand, and clearer water in the spring. High chlorine demand at opening is a genuinely expensive problem — a pool that burns through shock without holding a residual is a pool whose organic load was never dealt with the previous fall.
The granular formula is quick-dissolving and requires no dilution, so it broadcasts straight from the bottle with no bucket and no liquid to handle in cold weather. It’s suitable for all pool surfaces, works with chlorinated, brominated, ozone, and ionization systems, and dosing is straightforward at 1 lb per 6,000 gallons.
Pro Tip: Time your closing to water temperature, not the calendar. Close when water is consistently below about 60°F. Closing a warm pool leaves it warm enough under the cover for algae to keep growing on whatever organic material remains, which undoes most of what a careful closing was meant to accomplish. In the Intermountain West that usually means late September into October depending on elevation and the year. Waiting an extra two weeks for the water to cool costs nothing; closing early can cost you the entire spring opening.
Brand
BioGuard®
