A filter removes particles, but every cartridge adds pressure drop. Size filtration so water quality improves without pushing the pump below the chiller minimum.
1. What filtration does
Mechanical filtration removes suspended debris and helps keep larger particles out of pumps and heat exchangers. It does not automatically disinfect reused water.
2. Housing size
Large housings usually offer more media area and lower velocity. Pentair lists 15 GPM for its 20-inch Big Blue housing as a product flow specification. The cartridge still determines much of the real pressure drop.
3. Micron rating
Finer is not always better. Smaller micron media can capture finer material but may create more pressure drop and load faster. Choose the cartridge for the water-management job and hydraulic budget.
4. Pressure drop
ChillSizer represents filter restriction as a range when exact cartridge curves are unavailable. That range is combined with chiller and pipe resistance before the pump operating point is solved.
5. Turnover
Nominal turnover is volume divided by circulation flow. It is useful context, but the chiller's minimum GPH is still a separate hard equipment requirement. A fast theoretical turnover does not prove adequate disinfection either.
6. Filter fouling changes the system
A new filter is the best hydraulic case. Track performance as it loads. If cooldown worsens or flow drops, inspect the cartridge before blaming the compressor.
7. Filtration vs disinfection
Filtration, circulation and disinfection are different functions. CDC recreational-water guidance emphasizes disinfectant/pH testing, filtration maintenance and water replacement for pools/spas. A private cold plunge is not automatically the same venue type, so follow the exact water-treatment product and local guidance rather than copying a random dosing recipe.
References
Run your exact setup
Use your real tub, temperature, ambient, exposure, pump, filter and plumbing. ChillSizer checks thermal capacity and real operating flow together.
Open the System Designer