I have been told I need to put water into my basement floor drain (close to laundry tub and washer/dryer). How much water should I add? I have already added 4 pails of water and I still don't see the water level? How often should I add water Thanks

I think you were given this advice because someone suspects your trap has/will evaporated and allows sewer gas to get into your basement. It is more of a once a year preventive piece of advice. You should only see water standing at the top edge of your trap if you can even see it at all.

I have been told I need to put water into my basement floor drain (close to laundry tub and washer/dryer). How much water should I add? I have already added 4 pails of water and I still don't see the water level? How often should I add water Thanks

The trap holds about two inches of water minimum. You won't see the water level unless you remove the strainer and shine a light down in there. If the floor drain is unused then pour a pint of motor oil or anti-freeze in the trap and forget about it. Good luck, Tom