how many litres of water shall i feed my plants?

i was just wondering ive got 5 plants in soil in 5 litre pots how many litres shall i water them?

I have 10ltr pots and water them with 3ltrs water.
You should water them when a little water runs from the bottom of the pot then stop.

Agreed. Water until there is some run-off, then don't water again until the pots feel light, and the soil feels fairly dry below the surface.