Swim Spa Maintenance — A Complete Guide

Swim spas require the same core maintenance as hot tubs — water chemistry, filtration, regular cleaning — but at a different scale. With volumes typically ranging from 8,000 to 20,000+ litres, the quantities involved are much larger and the consequences of neglect more expensive. Here's what you need to know.

Water volume: the key difference

A standard hot tub holds 1,000–2,000 litres. A swim spa holds 8,000–20,000 litres. This changes everything:

• Chemical doses are proportionally larger — always calculate by volume, not by fixed amounts
• Drain and refill uses far more water and takes longer — typically 6–12 hours to drain fully
• Heating costs are higher — a heat pump is essentially mandatory for cost-effective operation
• Testing frequency is the same but errors take longer to correct due to the volume

Water chemistry for swim spas

The target parameters are identical to a hot tub:

• pH: 7.2–7.6
• Total Alkalinity: 80–120 ppm
• Free Chlorine: 3–5 ppm
• Calcium Hardness: 150–250 ppm

Because of the larger volume, changes take longer to take effect. Add chemicals, run filtration for a minimum of 4 hours, then re-test before adding anything else.

Filtration

Swim spas typically have multiple filter cartridges, and the filtration system must run more hours per day than a hot tub to keep the larger volume clean. Most manufacturers recommend 12–16 hours of filtration per day for heavily used swim spas.

Rinse filters weekly and deep clean monthly. Replace annually — swim spa filters carry a heavier load than hot tub filters.

How often to drain a swim spa?

Every 6 months for average use. The larger volume means TDS accumulates more slowly, extending the time between refills. However, if the water becomes difficult to balance or you notice persistent foam or cloudiness, drain earlier.

Allow 24 hours for a complete drain cycle. Use a pipe flush product first to clear biofilm from the exercise jets and current jets, which are particularly prone to build-up.

Exercise jet maintenance

The current jets in swim spas are high-flow and work hard. Check regularly for:

• Reduced flow from individual jets — often scale or debris in the nozzle
• Unusual noise from the current pump — swim spa pumps are typically larger than hot tub pumps and are expensive to replace
• Vibration — check all mounting bolts periodically

Cover and heat retention

Swim spa covers are large and expensive — a quality insulating cover is essential. Swim spas lose heat proportionally faster than hot tubs due to their surface area. A two-piece cover that seals well in the middle is better than a single-piece for large swim spas. Consider a thermal blanket on the water surface for additional insulation in winter.

Annual servicing

We recommend a full professional service annually for swim spas, covering: equipment inspection, filter replacement, pipe flush, seal checks on all jets and fittings, heater element inspection, control system test, and water analysis. Given the replacement cost of swim spa equipment, preventive maintenance is particularly important. Book a swim spa service.