Is not counting all pulses

[janvda]

I noticed a big variation when counting the pulses when filling a bucket of 10 liter.
FYI I maximally get 2 pulses for every 100 ml (2 pulses as a pulse is generated for both high and low).

It might be due to the

1. serial print statements in the interrupt handler => should be removed as this will disable interrupts during the printing.
2. dht reading taking a long time and blocking? interrupts
3. mqtt messaging taking a long time and blocking? interrupts
4. serial print statements outside interrupt handler taking a long time and blocking? interrupts