- Grain per gallon (gpg)
- The unit used to measure hardness: one grain per gallon is about 17 ppm (mg/L). The City of Prescott reports 4.3–7.6 grains; ADEQ’s study of Prescott-area wells averaged about 12.
- 32K, 48K, 64K
- A softener’s nominal size in thousands of grains. What it holds between regenerations is less; each sheet gives the supplier’s rating.
- Regeneration
- A softener’s cleaning cycle: salt water renews the resin, then it rinses to the drain — about 40 to 140 gallons on the tanks on these sheets, by size, plus the slow salt-water rinse (our arithmetic from the supplier’s settings).
- Backwash
- A filter rinsing itself by running water backward through the tank to a drain.
- Air draw
- How the Panther’s iron filter works: it keeps a pocket of air in the tank that turns dissolved iron and the rotten-egg gas into particles the media catches, and after each backwash it draws in fresh air, briefly emptying the tank of water to do it (the supplier).
- Pressure drop and Cv
- The water pressure a valve or tank costs at a given flow. A valve’s flow coefficient (Cv) is the flow, in gallons a minute, at which it costs 1 psi; the drop at other flows is (flow ÷ Cv) squared.
- Limited warranty
- A written warranty that does not meet every one of the federal conditions for a “full” warranty — for example, one that covers only the original buyer, or limits how long implied warranties last. A written warranty on a product costing more than $10 must be called “full” or “limited” (FTC). The supplier’s warranties on these packages say they are limited; each sheet’s Warranty row lists what is covered and what is excluded.
- Incidental and consequential damages
- Incidental damages are the costs of dealing with a failed part, such as inspecting it or shipping it back; consequential damages are the other losses it causes, such as water damage to a floor. The supplier’s warranties on these packages cover neither.
- Implied warranty
- An unwritten promise that state law attaches to a sale — the FTC calls implied warranties “unspoken, unwritten promises, created by state law” — the most common being that a product does what it is sold to do. A limited written warranty may limit how long they last.
- Not certified
- No independent certifier (NSF, IAPMO or WQA) lists the product for that claim, so the claim is the maker’s own. EPA does not certify treatment devices.
- MCL and MCLG
- EPA’s Maximum Contaminant Level is the highest level allowed in drinking water on a public system; the MCL Goal is the level below which there is no known or expected risk to health. For lead the goal is zero (the water-testing page).
- Downstream
- Further along the pipe. A softener connected downstream of the outdoor spigots leaves those spigots on unsoftened water.
- Free chlorine residual
- Chlorine still active in the water at your tap, as in chlorinated city water. A private well normally has none.
- IAPMO Z601
- A standard for scale-reduction devices such as salt-free conditioners. IAPMO tests and lists products against it; none of the Snow Leopards claims it.
- Media
- The material in a tank that does the work: resin in a softener, carbon, KDF, SP3 or arsenic media.
- Resin
- The small plastic beads in a softener that trade hardness for sodium (or potassium).
- Crosslink
- How tightly a softener resin’s beads are bonded, in percent: 8% is the standard grade, and a higher percentage makes a tougher bead. The Tiger 48’s invoice lists 8% crosslink.
- Mineral tank and salt tank
- The tall tank holds the media. The salt (brine) tank is the one you fill with bags of salt.
- Mid-plate
- A plate inside a tank that keeps two media apart (the supplier).
- KDF
- A copper-zinc media. The supplier says it reduces chlorine, heavy metals and hydrogen sulfide.
- GAC and catalytic carbon
- Granular activated carbon takes out chlorine taste and smell. Regular carbon cannot remove chloramine; catalytic carbon can reduce it (the supplier).
- Chloramine
- A disinfectant made from chlorine and ammonia that some cities use instead of chlorine.
- Clear-water iron
- Dissolved iron: the water runs clear from the tap, then turns orange or brown in the air.
- PFAS
- Man-made “forever chemicals” that break down very slowly. See the PFAS page.
- ppm, ppb, mg/L, µg/L
- Parts per million equal milligrams per liter (mg/L); parts per billion equal micrograms per liter (µg/L). Arsenic is usually given in ppb.
- ND (non-detect)
- Below the lowest level the lab’s method can reliably measure. It does not mean zero; your report gives the detection limit (the water-testing page).
- gpm and psi
- Gallons a minute, and pounds per square inch of water pressure.
- TDS
- Total dissolved solids: everything dissolved in the water, as one number. It says how much, not what.
- Turbidity (NTU)
- How cloudy the water is.
- Micron
- A millionth of a meter; a filter’s micron rating is the size of particle it catches.
- NSF/ANSI standards
- 42: taste and odor. 44: water softeners. 53: health claims such as arsenic, lead or PFAS. 55: UV. 58: under-sink reverse osmosis. 61 and 372: what a part adds to water — material safety, not performance. NSF, IAPMO and WQA test and list products; EPA does not certify treatment devices.
- Class A (UV)
- The NSF/ANSI 55 grade for UV units meant for water with harmful germs: a stronger dose with an alarm or automatic shutoff.
- Softener loop
- The pair of pipes a builder leaves for a softener, usually near the water heater or where the water comes in.
- Bypass valve
- A valve that sends water around the equipment, so the house keeps water while it is serviced.
- Air gap
- An open space between a drain line and the drain, so dirty water can never be pulled back into the system.
- Aqua Cat Series
- CreekWell’s own line of water-treatment packages, from the Kitten to the Lion: Neil chooses the parts, sizes each one to your water and installs it. Aqua Cat was also the business’s name until September 2026 (the name change). CreekWell does not manufacture the parts.
- The supplier
- The wholesale company CreekWell buys most of the parts through: Charger Water Treatment Products of Morton Grove, Illinois. Its name is on the HydroSplash under-sink RO (the Kitten and the Ocelot) and on the warranty papers linked from each sheet. Some parts are made by others: the HydroSplash by Vertex, the SP3 media by Watch-Water, the valves by Clack.
- Reference price
- A price published for planning and comparison only. It is not an offer, a quote or a bid: the work costs $1,000 or more (or is whole-house work), so Arizona requires a licensed contractor for it, and CreekWell is not offering it until its Arizona contractor licenses are issued. There is no date for the licenses. Why not yet?
- Arsenic III and arsenic V
- The two forms of arsenic in well water. Most treatment, RO included, works better on arsenic V; a standard lab panel reports the total, not the form. The University of Arizona says most Arizona aquifers contain arsenic V, so arsenic III is normally not a concern for Arizona well owners.
- Reverse osmosis (RO)
- Water pushed through a very fine membrane that holds back most dissolved solids; part of the water carries them to the drain.
- Recovery
- The share of the water going into an RO that comes out as purified water. At 50% recovery, a gallon goes to the drain for every gallon made.
- SP3, NAC and TAC
- Salt-free scale media. SP3 is Watch-Water’s product; its maker calls the process NAC. TAC media sold by other brands rest on a similar crystal-forming idea. None of them softens.
- Contact time
- How long water stays in a media tank. Carbon and arsenic media work better with more of it, so the flow through a tank is limited.
- Flow restrictor
- A small fitting that caps how fast water can pass through a tank, so the media gets the contact time it needs.
- Upflow
- Water entering a tank at the bottom and rising through the media. The supplier runs its salt-free media this way only.
- Pre-oxidation
- A step ahead of an arsenic or iron system that changes what is in the water so the next stage can catch it: arsenic III into arsenic V, usually with chlorine, since air does little to arsenic III (EPA); or dissolved iron into particles, with air or chlorine.
- pH
- How acidic or alkaline water is, on a scale of 0 to 14: 7 is neutral, lower is acidic, higher is alkaline. Several makers’ limits on these sheets include a pH range.
- Coliform and E. coli
- Bacteria a lab tests for. Coliform bacteria are a sign that germs could be getting into the water; E. coli, one kind, comes from human or animal waste (CDC). A lab report lists them separately: “Total coliform: present” means coliform was found, even when E. coli is absent. Some reports write it as A (absent: none found, a pass) or P (present). A positive test means the source is found and fixed first.
- MPN
- Most probable number: a lab’s estimate of how many coliform bacteria are in 100 mL of water. On a well, coliform should be zero, so 0, “<1” or “absent” is a pass.
- Mixed-bed
- The supplier’s name for a softener tank that holds more than one layer: on the Tigers, softening resin with a carbon layer in the same tank.
- Steady (service) flow and peak flow
- Steady flow is the rate a tank can treat water continuously and still do its job; a peak flow is a higher rate for a short time. The steady figures are the ones to plan on.
- In/out head
- A simple fitting on top of a tank with no timer or drain: water goes in and comes out, and the tank never backwashes.
- Anti-siphon device
- A fitting on a drain line that stops dirty water being pulled back into the equipment; codes call for it or an air gap.
- Tannins
- Natural matter from decaying plants that can tint water yellow or tea-colored. UV and arsenic media need water with little or none.
- Dissolved oxygen
- Oxygen carried in the water. Catalytic carbon needs enough of it to take out iron; Penn State says at least 4 ppm.
- Reject water (concentrate)
- The water an RO system sends to the drain, carrying what the membrane held back.
- Back pressure
- The push of a filling RO storage tank against the membrane. EPA says it makes a system less efficient than its rating: less water made, more to the drain.
- Leaching test (TCLP)
- EPA’s test of whether a used material would release contaminants in a landfill. Used-up arsenic media that passes it goes out as ordinary, non-hazardous waste.
- ppt (parts per trillion)
- A thousandth of a part per billion. PFAS limits are set in parts per trillion.
- UV dose (mJ/cm²)
- How much ultraviolet light the water receives. NSF/ANSI 55 Class A calls for 40.
- ADEQ
- The Arizona Department of Environmental Quality.
- Commissioning
- Starting up a new system and checking that it runs as its maker intends before it is handed over.
- Startup sample
- A water sample taken when a new system first runs, to check the result from the start.
- POE and POU
- Point of entry: treatment where the water comes into the house, so every tap gets it, as with the Jaguar’s AdEdge Medallion POE tanks. Point of use: treatment at one tap, as with an under-sink RO such as the Kitten.