Heavy rain can dilute sanitizer, shift pH, drop debris into the water, and overload the filter all at once. The right response is a storm recovery sequence, not random extra product.
Start with cleanup and circulation
Remove branches, leaves, and surface debris first. Storm cleanup is partly a chemistry problem, but it is just as much a debris and circulation problem.
If the filter is already under strain, extra chemistry can only do so much. Clear the obvious load before you decide what the water needs next.
Expect the numbers to move
Rain and runoff can dilute sanitizer, shift pH, and change how the pool responds to its usual routine. The same correction that worked last week may not be enough after a storm.
This is why storms deserve a fresh test instead of a repeated habit dose. The pool has new conditions, so it needs a new read.
Re-enter the routine carefully
Once debris is handled and the first correction is made, plan the retest rather than guessing later. Storm recovery often looks better, then slips again, if the follow-up never happens.
If clarity keeps dropping or sanitizer disappears quickly after a storm, move into diagnosis. That is a sign the pool is still cleaning up more than you can see.