Here is the place to control the bubble particles' lifetime and behaviour.
Buoyancy force
Buoyancy counteracts gravity and makes objects rise. With a value of 9.8 for the vertical direction you will get a natural behaviour, but it is also possible to accelerate or decelerate the bubbles with higher or lower values. You can also add horizontal components to influence the bubbles' motion. A click on "+" shows sliders.
Bubbles min lifetime
If you want to destroy the particles after a certain time then you can define a lifespan with “Bubbles min | max lifetime”. The actual lifetime will be somewhere between both values, and this value defines the lower limit. The value is given seconds.
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