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- Not sure it fits? Call (714) 541-6600
High Flow Whole House Carbon Filter with IPW WS 1.25 Timer Valve
A 1-1/4" high-flow backwashing carbon system that strips chlorine, chloramine, taste and odor from every tap in the house — built to order from 1.0 to 3.0 cubic feet, shipped unassembled or fully assembled.
This is the same recipe our Build Your System tool prices from — a complete backwashing carbon filter assembled from the individual parts we stock: a 1-1/4" IPW WS 1.25 electronic timer control valve, a NSF-listed Aquatrol mineral tank sized to the media charge, your choice of activated coconut shell carbon (chlorine, taste and odor) or catalytic carbon (chloramine and hydrogen sulfide), gravel underbed, internals, a quick-connect bypass with 1" NPT elbow adapters, and the correct drain line flow control for the tank. No salt, no brine tank, no chemicals — the valve simply backwashes the bed on a schedule to lift and re-settle the carbon. Pick Unassembled to ship as parcels and assemble in ten minutes, or Fully Assembled to receive it on a pallet, loaded and ready to plumb.
Key Performance Metrics
Pick the Media Charge for Your Home
| 1.0 cu ft · 9" × 48" tank | Up to ~5 GPM coconut / ~3 GPM catalytic. 1–2 bathrooms, apartments and small homes. |
| 1.5 cu ft · 10" × 54" tank | Up to ~7.5 GPM coconut / ~4.5 GPM catalytic. 2–3 bathrooms — the most common residential size. |
| 2.0 cu ft · 12" × 52" tank | Up to ~10 GPM coconut / ~6 GPM catalytic. 3–4 bathrooms. |
| 2.5 cu ft · 13" × 54" tank | Up to ~12.5 GPM coconut / ~7.5 GPM catalytic. 4–5 bathrooms or larger homes. |
| 3.0 cu ft · 14" × 65" tank | Up to ~15 GPM coconut / ~9 GPM catalytic. 5+ bathrooms, estates, light commercial. |
Size by peak flow, not by pipe size. Carbon needs contact time to work — a bed that is too small for your peak demand lets chlorine slip through. Count bathrooms, add one size if the home is over 4,000 sq ft, and go one size larger again if you are on chloramine and choosing catalytic carbon. Not sure? Run your address through our Build Your System tool and it will size and price the exact same build.
Which Valve Should You Buy?
This is the larger 1-1/4" valve. We also sell the identical carbon filter with the standard IPW WS1 valve for about $180 less, and most customers ask which to buy. The two valves are the same platform — same timer board, same programming, same seals, piston and backwash cycle, same tank, media and internals. The WS 1.25 has larger ports and internal passages, which raises the valve's own flow ceiling and lowers its pressure drop at a given flow. On a carbon filter that matters even less than on a softener, because carbon is sized by contact time: the media bed itself is rated at 5 GPM per cubic foot (3 GPM for catalytic), so even the largest 3.0 cu ft bed tops out around 15 GPM — well under what either valve can pass.
| Inlet / outlet | WS1: 1" · WS 1.25: 1-1/4" |
| Valve service flow (15 psi drop) | WS1: 27 GPM · WS 1.25: 34 GPM |
| Valve pressure drop at 10 GPM (approx.) | WS1: ~1.8 psi · WS 1.25: ~1.3 psi |
| Valve pressure drop at 15 GPM (approx.) | WS1: ~4 psi · WS 1.25: ~3 psi |
| What actually limits flow | The carbon bed: 1.0 cf ≈ 5 GPM, 1.5 cf ≈ 7.5, 2.0 cf ≈ 10, 2.5 cf ≈ 12.5, 3.0 cf ≈ 15 GPM (coconut; ~40% less for catalytic). Push past that and chlorine slips through regardless of valve size. |
| Price difference | About $180 more for the WS 1.25, same tank and media |
Get the WS1 if…
Your main line is 3/4" or 1" (nearly every home) and you are buying any size up to 3.0 cu ft for residential use. The bed, not the valve, sets your flow, so the $180 is better spent going up one media size — which actually improves chlorine removal.
Get the WS 1.25 if…
Your supply line is 1-1/4" or larger and you don't want to neck it down, you are running two or more filters in parallel or a light-commercial line, or incoming pressure is already low (under ~50 psi) and you need to shave every psi of drop through the treatment train.
Match the plumbing, not the price tag. A WS 1.25 connected with 1" adapters into a 1" main gains you nothing — the pipe is the restriction. If you buy the WS 1.25, ask us for 1-1/4" connection adapters so the whole path is full-size. If your main is 1", buy the WS1 and put the savings into a bigger carbon bed.
Everything Needed for a Working System
- IPW WS 1.25 electronic timer backwash valve — 1-1/4" high-flow control head with weather-tight cover
- Aquatrol fiberglass mineral tank — NSF-listed, 9" to 14" diameter to match the media charge
- Carbon media — 1 cu ft bags of activated coconut shell or catalytic carbon, filled to the selected size
- Gravel underbed — supports the bed and spreads backwash flow evenly
- Distributor tube with lower basket + upper basket — 1.05" riser internals
- Bypass valve + 1" NPT male elbow adapters — isolate the filter without shutting off the house
- Drain line flow control (DLFC) — pre-selected for the tank diameter so the bed lifts without blowing carbon to drain
- Power supply — plug-in transformer, dry locations
Unassembled vs. Fully Assembled. Unassembled ships as separate parcels (tank, valve, media bags) by ground — lowest cost, and loading a tank takes about ten minutes with a funnel. Fully Assembled adds freight: the tank is loaded, the valve is mounted and sealed, and the unit arrives on a pallet ready to set in place. Assembled systems weigh roughly 70–185 lb depending on size, so plan for help moving it.
System Construction
| Control Valve | IPW WS 1.25 high-flow electronic timer valve, 1-1/4" inlet/outlet, backwash filter configuration (3-cycle: backwash, rinse, service) |
| Valve Body | Fiber-reinforced composite, 2-1/2" – 8 NPSM tank thread, NSF/ANSI 61 and 372 listed; IP54/IP55 electronics enclosure |
| Control Board | Solid-state time-clock control, 1–28 day backwash override, adjustable cycle times, non-volatile memory, coin-cell backup with power-outage carry-over |
| Power | Dual-voltage plug-in transformer, 100–120V or 200–240V AC, 50/60 Hz; 15 VDC to the valve |
| Mineral Tank | Aquatrol poly-lined fiberglass-wound vessel, 2-1/2" – 8 top opening, 150 psi rated; 9x48 / 10x54 / 12x52 / 13x54 / 14x65 by media size |
| Activated Coconut Shell Carbon | High-iodine coconut shell GAC for chlorine, taste, odor and VOC reduction; 5 GPM/cu ft design service rate |
| Catalytic Carbon | Enhanced coconut carbon for chloramine and hydrogen sulfide; 3 GPM/cu ft design service rate for added contact time |
| Backwash Design Rate | 10 GPM per sq ft of bed area; DLFC sized per tank (9" ≈ 5.3 GPM, 10" ≈ 6.5, 12" ≈ 9.0, 13" ≈ 10.0, 14" ≈ 17.0 via 1" drain fitting) |
| Underbed | Washed gravel, approx. 12 lb per cubic foot of media |
| Bypass | Quick-connect bypass with two 1" NPT male elbow adapters (1-1/4" adapters available on request) |
| Operating Pressure | 20 – 125 psi; install a pressure regulator above 80 psi |
| Water Temperature | 35 – 110°F; indoor or shaded, non-freezing location |
| Drain | 3/4" drain line minimum; 1" recommended on 13" and 14" tanks |
| Assembled Weight (approx.) | 1.0 cf ≈ 70 lb · 1.5 cf ≈ 95 lb · 2.0 cf ≈ 125 lb · 2.5 cf ≈ 150 lb · 3.0 cf ≈ 185 lb (tank + media + gravel + valve) |
Why a High-Flow Backwashing Carbon System
No Pressure Drop Penalty
A 1-1/4" valve rated to 34 GPM keeps full pressure on 1-1/4" mains and parallel or light-commercial installs where a 1" head would start to add drop.
Self-Cleaning Bed
Scheduled backwash lifts the carbon, flushes trapped sediment to drain, and re-stratifies the bed — no cartridges to change, no channeling.
Media Matched to Your Water
Coconut shell carbon for chlorinated city water; catalytic carbon when your utility uses chloramine or you are fighting sulfur odor on a well.
Years Between Media Changes
A properly sized bed typically runs 3–5 years on municipal water before the carbon is exhausted — then re-bed it with a bag of media, not a new system.
Protects Everything Downstream
Removes the chlorine that attacks softener resin, RO membranes, rubber seals and water heater anodes — the right first stage in any treatment train.
Built from Stock Parts
Every component is a part we sell individually, so service parts are always one click away and nothing is proprietary.
Getting Set Up
- Set the tank on a level, non-freezing surface near a floor drain or standpipe. Unassembled systems: tape the riser tube, pour in the gravel, then the carbon, remove the tape and thread on the valve hand-tight.
- Snap the bypass onto the valve, then plumb the inlet and outlet. Install upstream of any softener or RO so the carbon protects them from chlorine.
- Run a drain line to an air gap. Keep it as short and straight as possible — backwash on a 12" or larger tank moves 9–17 GPM.
- With the bypass in bypass, open the inlet slowly to fill the tank and purge air through the drain, then soak new carbon for 30–60 minutes to release fines.
- Plug in the valve, set the time of day and backwash schedule, and run a manual backwash and rinse until the drain runs clear before putting the system in service.
Backwash on a schedule, not on demand. Carbon does not need frequent backwashing — every 7 to 14 days is typical on city water, less often on very clean water. Over-backwashing wears media; under-backwashing on turbid water lets the bed pack. If you are on a well with iron or sediment, put a sediment or iron stage ahead of this filter.
Where This System Fits
Designed for whole-house point-of-entry treatment of chlorinated or chloraminated municipal water in homes from 1 to 5+ bathrooms, and as the carbon stage in a multi-stage softener or well-water train. Choose catalytic carbon if your water utility reports chloramine (most of Southern California and many large utilities do) or if you have a rotten-egg sulfur odor; choose activated coconut shell for straight chlorine, taste and odor. This system does not remove hardness, iron, bacteria or dissolved solids — pair it with a softener, iron filter, UV or reverse osmosis as needed. Every variant here is priced identically to the same build in our Build Your System tool, so you can configure there and buy here, or vice versa.
Built in California
Assembled and shipped from our Santa Ana facility. Unassembled ships ground; assembled ships freight on a pallet.
Stock Components
NSF-listed tank, valve and media — every part is a catalog item we stock and support.
Build Help
Not sure which size or carbon you need? Call (877) 541-6603 and we will size it from your water report.
