Waste tank smell

[Brockhole]

Why do I get waste tank smells inside when travelling?(1979 Minnie Winnie) Shouldn't the vent system take care of this? What chemical could I add to the tanks to prevent this, bearing in mind that the tanks are usually emptied at home, into my septic tank? I do't want to use anything that will upset the action of the septic tank.
Thanks guys.

[Brockhole]

Why do I get waste tank smells inside when travelling?(1979 Minnie Winnie) Shouldn't the vent system take care of this? What chemical could I add to the tanks to prevent this, bearing in mind that the tanks are usually emptied at home, into my septic tank? I do't want to use anything that will upset the action of the septic tank.
Thanks guys.

[bldrbob]

I found my shower dwain trap would empty while traveling.I solved the problem by putting a baggie full of water over the drain and closing all the sink drains.
BOB

[Wallaby Dan]

bidrbob, is right if the drains loose the water in the traps the fumes will backdraft into the coach. The other thing is find a rubber ball about the size of the toilet throat. The water sometimes will work around the seal and that will allow the backdraft to apply here as well. The rubber sponge type ball would be best.
Brockhole, Welcome to the forum and the vintage RV site!