Three signs, in order of likelihood. First, yellow tint returning even after a fresh regeneration cycle. Second, a fishy or musty odor in the treated water that a cleaning cycle (salt plus baking soda) no longer fixes - that is organics permanently fouled into the bed. Third, the bed is simply old: well-maintained tannin resin typically serves for years, but no bed lasts forever. Before buying, rule out iron: it causes the same yellow symptom and a rebed will not fix it. A certified lab test reporting Tannin-Lignin plus iron tells you which problem you have.

If your system is a salt-regenerated anion exchange tannin filter (a mineral tank, a softener-style control valve, and a brine tank), yes. That covers our Fleck 5600SXT tannin system, our 6 and 10 GPM whole-house systems, and virtually every residential tannin filter on the market regardless of brand. What matters is volume: measure your tank diameter and height, check the sizing table in the Rebedding tab, or call us with the numbers.

Fouling resistance. Tannin molecules are large organics that styrene-based anion resins grab but cannot release during regeneration, so a styrenic bed loads up with organics and quits, often within a season or two. Purolite A850's polyacrylic gel structure releases captured organics to the drain every brine cycle - Purolite's datasheet calls out its excellent resistance to organic fouling. That difference is the entire service life of the bed.

By tank size: a 9x48 tank holds about 1 cubic foot (1 box), a 10x54 holds about 1.5 cubic feet (2 boxes with media left over), and a 13x54 holds about 2.5 cubic feet (3 boxes with media left over). The diameter and height are printed on the tank label. If you'd rather not buy a full extra box for a half-foot top-off, call us and we'll figure out the cheapest path.

Yes - it is a half-day job with basic tools. Bypass the system, pull the valve, vacuum out the spent resin, rinse the tank, check the riser tube, pour in the new media with the riser capped, reinstall the valve, and run a manual regeneration. No plumbing changes, because the tank and valve stay. The full step-by-step is in the Rebedding tab, and we will walk you through it on the phone 7 days a week if you want company.

Years, if it regenerates frequently. Organics that sit on an anion bed too long migrate into the resin matrix and become hard to strip, so program the valve to regenerate every two to three days rather than stretching capacity. Two other life-extenders: keep hardness off the bed (a softener upstream) and keep sediment out (a pre-filter). Do that and the salt is your only ongoing cost until the next rebed, years out.

No. Spent residential tannin resin is ordinary solid waste: bag it and put it in the trash, following any local guidance. The organics it captured are natural plant compounds, not hazardous chemicals. Never rinse loose resin down a drain - the beads can settle in traps and plumbing low spots.

Yes. Purolite A850 is certified by the WQA to NSF/ANSI-61, the standard covering materials in contact with potable water, and it is also Kosher and Halal certified. After a rebed, run a manual regeneration and flush until the water runs clear before returning the system to service - standard practice for any fresh media bed.