Civic 2013 reducing coolant.
from last two weeks its reducing coolant, almost filled reservoir 3 times in two weeks and approximate 1ltr direct in radiator.
always used coolant from dealership (from last 2 weeks filling with tap water)
both fans are working fine.
no buble in radiator.
no water flushing out of radiator.
no rust and oil mix.
what r the possible causes. i drove this car 195k Kms.