20-Micron Cold Plunge Filters

These are the 20-micron replacement filters that keep a cold plunge clear. Sized specifically for our cold plunges, each captures roughly 95% of debris so the water stays fresh and crystal-clear between changes.

Filtration is what separates a real cold plunge from a tub of cloudy ice water — and filters are a consumable. Keeping fresh ones on hand is the small habit that keeps the plunge inviting rather than a chore.

A plunge filter has one adversary: the invisible load a human body sheds into forty-odd litres of cold water. Skin cells, body oils, sunscreen, lint, pollen — none of it visible per session, all of it cumulative. At 20 microns this cartridge strips that load down to roughly ninety-five percent per pass, which across a day of continuous circulation means the water you see through is the water you're actually in.

Micron ratings are a real trade, not marketing tiers: a 50-micron cartridge passes the haze that makes water feel used; a 5-micron chokes a plunge pump within days and starves circulation. Twenty microns is where clarity and flow meet for this class of circuit — it's the spec our own plunges run from the factory, and the number to match if you're filtering anything comparable.

Reading your filter is simple diagnostics: a grey, evenly-loaded cartridge on schedule means the system is working; a slimed cartridge early means the waterline needs its wipe-down routine; a clean cartridge at week six means your circulation isn't running long enough hours. The consumable is also the instrument.

Swaps are a two-minute habit: circulation off, housing open, cartridge out, new one seated, hands washed. No tools, no draining, no chemistry event. Batch owners standardize it to the first of the month — the calendar, not the memory, keeps water honest.

Six to a pack is deliberate math: solo daily use runs a cartridge three-to-four weeks, so one pack is roughly two seasons; shared tubs run hotter cycles and a pack covers a season. Either way the reorder rhythm is twice a year — infrastructure, not errands.

Water chemistry context for the curious: a filtered, circulated plunge at 3 degrees is a genuinely hostile environment for microbial growth — cold suppresses it, movement denies it settling time, and the cartridge removes its food supply. That triad is why chemical-free plunge water is a real regime and not wishful thinking; the filter is the load-bearing member of it.

Stocking logic mirrors any consumable that guards an asset: the tub and chiller are the investment; the cartridge is the insurance premium. Six-packs on subscription-style reorder are how our longest-running plunge owners handle it — the box arrives before the calendar asks.

One operational tip that extends every cartridge: run the circulation on a schedule rather than continuously when the tub is idle — eight-to-twelve hours daily keeps water polished while halving the media's dirt-hours. The chiller app's scheduler handles it; the filter budget notices.

And a buying-pattern note: filters are the item our plunge owners most regret under-stocking — the failure mode is a loaded cartridge on a Friday with no spare until Tuesday, three days of cloudy water, and a dented habit. Two packs a year, standing order, solved forever.

Filters close the plunge's ownership loop: the chiller sets the temperature, the tub holds the water, and the cartridge decides what that water is like to be in. Of the three, only the cartridge asks for anything ongoing — and what it asks is a two-minute swap and a calendar entry. Owners who honour that ask get spa-clear cold water indefinitely; the pack of six is simply that promise in inventory form.

They also make the practice portable across our line: the same cartridge serves the Portable-plus-chiller starter rig and the Elite on a spa floor, so upgrading tubs never strands your filter stock. Standardization is a small kindness at reorder time.

Compatibility documentation is printed inside the pack lid — housing dimensions, flow rating, and the swap procedure in four steps — so the person doing the change never needs the website open. Small operational courtesies like this are why the consumables in our line get reordered rather than substituted: the product that makes maintenance effortless is the product that keeps getting used, and clear water is downstream of exactly that convenience.

Order once, calibrate forever: after the first pack you'll know your tub's true cadence, and the reorder becomes as automatic as the swap itself.

• 20-micron replacement filters engineered for cold plunge tubs
• Drop-in replacements sized for our plunge filtration housings
• Captures roughly 95% of suspended debris per pass
• Holds plunge water clear and fresh between changes