Water care
Hot tub water care: chemistry made simple for Fraser Valley water
Balanced hot tub water comes down to four numbers: alkalinity, pH, calcium and sanitizer. Here's how to keep them in range, and why most Fraser Valley tap water needs calcium added.
Hot tub water care comes down to keeping four things in range: total alkalinity, pH, calcium hardness and sanitizer. Balance them in that order, test two or three times a week, shock after heavy use, and the water stays clear and comfortable. In much of the Fraser Valley the tap water is very soft, so most new fills here need calcium added, which surprises a lot of new owners.
The ranges below are the ones commonly recommended. Your tub's owner's manual is the final word, especially for anything the warranty depends on.
The four numbers that matter
| What you test | Commonly recommended range | Why it matters |
|---|---|---|
| Total alkalinity | about 80–120 ppm | Buffers pH so it doesn't swing |
| pH | about 7.4–7.6 | Comfort for eyes and skin, sanitizer strength, protects equipment |
| Calcium hardness | commonly 150–250 ppm | Too low: foamy, aggressive water. Too high: scale |
| Sanitizer | chlorine or bromine, often about 3–5 ppm | Kills bacteria and breaks down organic waste |
Total alkalinity
Alkalinity acts as a cushion for pH. When it's low, pH bounces around with every soak; when it's high, pH creeps up and is hard to bring down. Fix alkalinity first.
- To raise it: add an alkalinity increaser (sodium bicarbonate).
- To lower it: add pH decreaser in small doses with the jets off, wait, retest, then run the jets with the cover open. The aeration brings pH back up without bringing alkalinity back with it. It takes a few rounds.
pH
Once alkalinity is in range, adjust pH.
- pH too high (cloudy water, scale, chlorine that seems weak): add a pH decreaser, usually sodium bisulfate.
- pH too low (itchy eyes, corrosion risk for heaters and fittings): add a pH increaser, usually sodium carbonate.
Add a little at a time with the pumps running, wait at least 15 to 20 minutes, and retest. Chasing pH back and forth usually means alkalinity is out.
Calcium hardness
Water with too little calcium tends to foam and can be aggressive toward metal parts, heater elements and seals. Water with too much leaves crusty scale on the shell, jets and heater. A calcium hardness increaser raises it. Lowering it means partly draining and refilling with softer water.
Sanitizer
Chlorine and bromine are the two common choices.
- Chlorine (often granular dichlor in hot tubs) works fast and is easy to measure. It's used up quickly at hot tub temperatures, so it needs topping up after use.
- Bromine (often tablets in a floater or feeder) is more stable in hot water and many people find it gentler on the nose. It's slower to adjust.
Ozone and UV systems help sanitizer work and can cut how much you use, but they don't replace it. A saltwater system makes chlorine from dissolved salt; the water still needs testing and balancing.
What Fraser Valley tap water means for your tub
Published hardness figures for local water systems vary a lot, and they change how you start every fill:
| Where | Published hardness (mg/L as calcium carbonate) | What it usually means |
|---|---|---|
| Langley City and most of Langley Township | about 2 | Very soft: add calcium on every fill |
| Maple Ridge | about 2 | Very soft: add calcium on every fill |
| Abbotsford and Mission | about 5 | Very soft: add calcium on every fill |
| Surrey | about 21 | Soft: add calcium |
| Chilliwack | about 51 | Moderately soft: some calcium needed |
| Langley Township, Acadia well system | about 65 | Moderately soft: some calcium needed |
| Aldergrove | about 163 | Hard: likely already in range, watch for scale |
Hardness in mg/L is roughly the same as ppm on a test strip. So a fresh fill in Langley or Maple Ridge starts near zero calcium and needs calcium increaser to reach the range your manual asks for. Skipping it is one of the most common causes of foamy water in soft-water areas.
In Aldergrove, the fill water may already sit inside the usual range, so don't add calcium without testing. Hard water combined with high pH is what leaves scale, so keep pH under control and consider a scale and stain control product.
If you fill from a private well, have the water tested for metals as well. Iron and other metals can stain the shell, and a metal sequestrant added at fill time helps keep them in solution.
Water suppliers adjust treatment over time, so test your own fill water rather than relying on the table.
A simple testing routine
- Two or three times a week: test sanitizer, pH and alkalinity with strips or a drop kit, and adjust.
- After heavy use or a party: shock the water and top up sanitizer.
- Weekly: shock, even with light use, to break down oils and waste the sanitizer has bound up.
- Each fill: test calcium, adjust it first along with alkalinity, then pH, then sanitizer.
- Every few months: drain, clean and refill. How often depends on how much the tub is used; our maintenance guide covers it step by step.
Always add chemicals one at a time with the jets running and the cover open, and let each one circulate before adding the next. Never mix chemicals together, and store them dry, closed and apart.
Shocking a hot tub
Shock is a large dose of oxidizer that clears out oils, sweat and other waste.
- Non-chlorine shock (potassium monopersulfate) oxidizes waste without raising chlorine much, so you can usually use the tub again soon after. Check the label.
- Chlorine shock oxidizes and sanitizes. Leave the cover open for a while afterward so gas can escape, and wait until chlorine drops back into range before soaking.
Why hot tub water foams, and how to stop it
Foam is almost always a sign that something has built up in the water:
- body oils, lotions, makeup and hair products
- laundry detergent left in swimsuits (rinse them in plain water)
- low calcium hardness, very common with soft Fraser Valley water
- old water that's overdue for a drain and refill
A defoamer knocks foam down quickly, but it treats the symptom. Shock the water, check calcium, clean the filter, and if the water is a few months old, drain and refill. A quick rinse in the shower before soaking prevents most of it.
Supplies to keep on hand
A basic kit: test strips, sanitizer, non-chlorine shock, pH increaser and decreaser, alkalinity increaser, calcium hardness increaser, filter cleaner, and a spare filter so one can dry while the other is in use. Our chemicals and supplies page explains what each product is for.