Jets are weak or some seats have very low water pressure even when pumps are on high speed.

Safety first: Turn off power at the GFCI breaker before removing jets or opening unions.

• Clean filters: Remove and thoroughly rinse filter cartridges. Try running the spa briefly without filters to see if jet pressure improves.
• Open all valves: Ensure all diverter valves and air controls on the spa shell are fully open and not stuck between positions.
• Bleed pump: Loosen the pump union slightly to release trapped air, then retighten and test.
• Clean jets: Twist and pull removable jet inserts out of their housings. Soak them in a spa jet cleaner or vinegar solution to remove scale and debris, then reinstall.

If pressure remains low on one pump only, that pump or its impeller may be damaged and require replacement.