Smell in basement, read that if you poured water down drain it would fix it. I tried all three drains by pouring water in them. The smell (sewer) diminished for a day, but the next day it was back. Should I keep pouring water in the drains or call a plumber.

. Should I keep pouring water in the drains or call a plumber.
Try this for the smell. Tonight before bedtime Take a 1/2 gallon of bleach and pour it down the drain and let set over night. Next morning ,(and this is important) flush out the drain with two large pans of boiling water to loosen the grease and flush the mess out. The bleach will make the hair slippery and began to dissolve it and the hot water will melt the grease and flush the mess away.
. This should make your drains smell better. With all chemicals used in drain cleaning proper ventilation should be observed. Good luck, Tom