Most likely it is caused by an air leak somewhere in the system allowing the filter to drain back to the pool through the suction lines. You will probably see DE in the pump pot as well.
From the core of the Earth and plate tectonics.
where does the radient energy transmitted to earth come from
the center of the Earth
yes natural gas does come from the earth (very true in every situation);
rotation of the earth's core
From the core of the Earth and plate tectonics.
Gravity
Yes and they also go down the drains
Too much oil, excessive crankcase pressure ( bad piston rings ) or both. pressure causes oil to come the filter tude and capilarity is also a factor. pressure causes oil to come the filter tude and capilarity is also a factor.
Friction
the mass of the earth exerts gravity on all objects around it
wind does originally come from the sun the sun heats the earth the heated earth causes wind
The sun gets closer to the earth and causes the earth to a perfect climate for plants and animals to procreate.
The Sun.
It could, have the system checked for codes to know possible causes.
A bad PCV valve or a problem in the PCV system will cause this
can fleas climb up drains