Water Balance
Alkalinity
Low alkalinity (below 80 mg/L): pH becomes unstable. Any external factors — rain, adding chemicals, swimming — can cause sharp pH fluctuations.
High alkalinity: pH becomes difficult to adjust. Even adding acid lowers it slowly and reluctantly.
Normal range: 80–120 mg/L — the working range that ensures system stability.
ORP (Oxidation-Reduction Potential)
If chlorine is the “soldier,” ORP shows its actual effectiveness right now.
Function: The device measures the water’s potential in millivolts (mV).
Meaning: It shows how actively the water can kill bacteria at the moment.
Connection with pH: High pH reduces chlorine effectiveness, lowering ORP even if chlorine levels are sufficient. In other words, chlorine is present but works weaker.
Normal range: For safe swimming, ORP should typically be above 650–700 mV, indicating high disinfecting capacity.
Calcium Hardness
Water seeks calcium balance.
Low hardness (soft water): Water becomes aggressive and can:
- Damage tile grout and finishing materials
- Harm concrete surfaces
- Accelerate equipment wear (especially with low pH)
High hardness (hard water): Excess calcium precipitates:
- Scale forms at the waterline
- Deposits inside pipes and equipment
- Heater and filtration efficiency decreases
TDS (Total Dissolved Solids)
TDS is the sum of everything dissolved in water: minerals, salts, chemical residues, and organic contaminants.
“Old water” effect: Over time, TDS inevitably rises. Higher TDS changes water properties and behavior.
Problems:
- Chemicals work less predictably
- Cloudiness may appear without obvious cause
- Increased risk of scale and equipment wear
Guidelines: It’s important to monitor not only absolute values but also growth relative to fresh water. Significant problems usually appear around 1500–2000+ mg/L.
Solution: Reducing TDS is only possible by partially replacing the water.
Water Temperature — The Process Catalyst
Temperature affects everything: the speed of chemical reactions and microbial activity.
Chemical consumption: Warmer water accelerates chemical use. Chlorine breaks down faster (including under sunlight) and is consumed more quickly oxidizing contaminants. Microbes and algae also multiply faster.
Saturation: In warm water, calcium stays dissolved less effectively and begins precipitating on surfaces — tile, waterline, and equipment.
Implication: The warmer the water, the harder it is to control.
Conclusion
Water balance is not a single number — it is a combination of parameters working together.
Think of it like a car: checking the fuel level alone doesn’t tell you if the engine, oil, and brakes are in good condition.