Hot Tub & Spa Chemistry Calculator | PoolDose

Professional chemistry tools for hot tubs and spas. Calculate precise chemical dosages for small water volumes to ensure safe and clean soaking. Smaller volumes of water react much faster to chemicals, making accurate measurement essential for maintaining a healthy spa environment.

FAQ

Why is spa chemistry different from pool chemistry?

Spas have a much higher bather-to-water ratio and warmer temperatures. This causes chemicals to be used up faster and pH to drift more rapidly than in a large pool.

How often should I drain my hot tub?

As a general rule, you should drain and refill your hot tub every 3-4 months to remove accumulated dissolved solids that make the water difficult to balance.

Can I use pool chlorine in my hot tub?

While the chemicals are similar, you must be very careful with dosages. We recommend using products specifically labeled for spa use to avoid damaging your equipment.