Fryer oil change

We bought the deep fryer
And for filteration boight the vito filter system
But still when we change oil how we will know.

Does it cook slow or discoloration

There are several indicators:

•The oil will have a strong odor

•the oil will smoke

•The food will come out soggy when the oil is old
Because the food absorbs oil


•We use a method that keeps our fried food consistent day after day after day.

-at the end of the day we discard about 30% of the used oil.
-we filter the remaining oil
-we then add fresh oil to get it back to the fill line.

Oh yes i think this we can do on every busy night discard 30% oil
And add new oil in that.

Thank you for help.

Make sure you filter the oil after you discard the used oil with a clean fresh filter everday