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MyWaterClub 3-Stage Whole House System — Big Blue, 1″ NPT
WHS-3SGCACB-10BB
Is this your system?
- ✓Three blue housings on a white wall bracket
- ✓1″ NPT ports with brass threaded inserts — you can see the brass inside the inlet and outlet
- ✓Big Blue housings — wide, roughly 4.5″ across, not slim
- ✓Red pressure-release button on top of each black cap
Two housings instead of three? Slim 2.5″ housings? 3/4″ ports? Find your model →
At a glance
| Stages | 3 — Sediment, GAC, Coconut Carbon Block |
| Cartridge size | 10″ × 4.5″ Big Blue |
| Connections | 1″ NPT female, brass threaded inserts |
| Overall size | 22¾″ W × 16¾″ H × 8½″ D |
| Operating pressure | 20–85 PSI |
| Water temperature | 40–100 °F, cold water only |
| Weight assembled | About 27 lb |
Installation manual
Mounting, plumbing connections, first flush, and step-by-step filter changes.
Replacement filters
Prefer to buy cartridges individually, or replace only one stage?
| Stage 1 SED5-10BB · 5 µm |
Sediment — dirt, silt, sand, rust. Change every 3–6 months. |
| Stage 2 GAC-10BB · 25 µm |
Granular carbon — bulk chlorine, taste, odor, VOCs. Every 6–12 months. |
| Stage 3 CACB-10BB · 10 µm |
Coconut carbon block — final taste polish. Every 6–12 months. |
Intervals are typical estimates. Change sooner if water pressure drops, if taste or odor returns, or if the sediment cartridge looks visibly dark. Stage order matters — sediment always goes in the first housing on the inlet side.
Different water? Swap a stage
The standard set handles sediment, chlorine, taste and odor. These need different media — all the same 10″ × 4.5″ size, so they drop straight into your existing housings.
| If your water has… | Swap in |
|---|---|
| Chloramine instead of chlorine | CAT-10BB catalytic carbon in Stage 2 |
| Dissolved iron, manganese, hardness | IRON-10BB iron-reduction resin |
| Limescale in heaters and appliances | PHO-10BB salt-free scale inhibitor |
| Heavy visible sediment on well water | SED5-PLT-10BB washable pleated, Stage 1 |
Parts & wear items
These wear out on a different schedule than your cartridges. Replacing them on time prevents the two most common problems — slow leaks at the housing seal, and cracked housings.
Housing Wrench — WRENCH-10BB
Keep one by the system rather than hunting for it mid-change
Changing your filters
- Shut off the water supply to the system and open a downstream tap to drop the pressure.
- Press the red pressure-release button on each cap. This is what keeps the change dry.
- Put a bucket underneath. Each housing holds roughly a gallon.
- Unscrew each housing with the wrench — turn clockwise when viewed from below.
- Lift out the old cartridge. Rinse the housing and wipe the O-ring grooves clean.
- Fit the new cartridges in flow order: Sediment first, GAC second, Coconut Carbon Block last.
- Check the O-rings are seated without twists. Lightly grease with food-grade silicone if they look dry.
- Hand-tighten, then a small turn with the wrench. Do not overtighten.
- Turn the water on slowly, then flush to drain for 5–10 minutes — new carbon releases harmless fines at first.
Watch the seams for a minute before walking away.
Troubleshooting
| Symptom | Likely cause and fix |
|---|---|
| Pressure has dropped | Sediment cartridge is loaded. Change Stage 1 first — it is usually the only one needed. |
| Taste or smell has come back | Carbon is exhausted. Change Stages 2 and 3. If it returns quickly, your supply may use chloramine — see the swap table above. |
| Slow drip at the housing seam | O-ring has taken a set, or grit is holding it off its seat. Clean the groove and fit a new O-ring set. |
| Leak a new O-ring did not fix | Housing itself is fatigued. Replace it — plastic under constant pressure has a service life of 3–4 years. |
| Black specks in the water | Carbon fines after a change. Harmless. Flush to drain for another 10 minutes. |
| Cloudy or milky water | Usually trapped air after a change. Run a tap for a minute and let it stand — it should clear from the bottom up. |
| Housing will not unscrew | Pressure is still in the line. Shut the supply off, open a downstream tap, and press the red button again. |
Still stuck?
Send us a photo of your system and tell us what it’s doing. Get in touch →
Please note: Filter life and reduction performance depend on your water chemistry, pressure and usage, so results vary from home to home. This system is a sediment and carbon filter — it is not a certified microbiological purifier, it does not soften water, and it does not remove dissolved minerals. It is not a substitute for testing your water. Descriptions use general, qualified language and are not health claims.