I wash out black tank eveytime I dump put chems' in and within 3 or 4 day you can't stand the smell and I use lots of water ??

Try The Geo Method. It'sIt's been very effective for us, but you need to follow it as written.

FT for 6 yrs............20 (+) yrs of camping and don't use chemicals.Smells inside rig from black means toilet bowl seal is not holding water, toilet floor flange not sealing, cracked vent line OR running bathroom exhaust fan when flushing.Grey tanks can smell just as bad as black."p" traps dry (no water), 'air admittance valve' not closing properly (located under bathroom and kitchen sinks on drain line between 'p' trap and tank...they should open when draining tank so 'p' water isn't sucked out and then close)OR cracked vent lineAfter draining and flushing black tank (water runs clear---no chunks) are you adding a couple gallons of water back into tank so bottom stays wet?You want to keep bottom of tank wet so 'stuff' doesn't stick and dry out.Also are you waiting until tank is pretty much full before dumping.You want a high liquid level when dumping to carry solids/tp out and down drain line.....otherwise you can end up with 'piles' which WILL stink.

I just replaced toilet flange seal and the toilet holds water overnight

I added a 360 on the roof vent - no more smell.

ROADSTARJR wrote:I just replaced toilet flange seal and the toilet holds water overnightThen the vent must be leaking. As the other poster pointed out you should not have any smell from the tank except maybe a tiny bit when flushing other than that it should be sealed. I had a cracked vent pipe on my 89 Jamboree and that became unbearable with the four kids and mom and dad on a long road trip. Once i found it and fixed it no more smell!

full timing with black water Q | Good Sam Community

Roads_Less_Trav
Explorer II
May 26, 2013
Every time we dump the black tank, after it's empty, we pour two or three 5-gallon buckets of water into the toilet. We keep dumping in buckets of water until the water runs clear in the sewer hose.

What happens is that the solids pile up right below the toilet, and even if you have a fresh water flush system for your black tank (we have one on our fiver), it doesn't dislodge those solids.

It is amazing that after emptying the tank it sometimes takes 3 buckets of water for the water to run clear. Usually it takes only two.

We have a transparent connector on our black water hose so we can see when the water is running clear...
brirene
Explorer
May 17, 2013
trb46 wrote:
BarbaraOK wrote:
Put rotating vanes on BOTH the black and grey tanks. Lots of water is all you need.

Barb

I'll admit I'm fairly new at RVing. I've never heard of "rotating vanes." What are they?

Referring to vent covers that rotate with the wind direction and draw odors out, such as this one.
trb46
Explorer
May 17, 2013
BarbaraOK wrote:
Put rotating vanes on BOTH the black and grey tanks. Lots of water is all you need.

Barb

I'll admit I'm fairly new at RVing. I've never heard of "rotating vanes." What are they?
dave17352
Explorer
May 16, 2013
phil crouch wrote:
Look inside the bowl and see if there is an overflow hole near the top... We plugged ours and no more smell...

I forgot about that. I did that in my 98 lance camper and got rid of smell also.
phil_crouch
Explorer
May 16, 2013
Look inside the bowl and see if there is an overflow hole near the top... We plugged ours and no more smell...
ROADSTARJR
Explorer
May 16, 2013
Thanks' to all I got some work to do
BarbaraOK
Explorer
May 16, 2013
Put rotating vanes on BOTH the black and grey tanks. Lots of water is all you need.

Barb
HDrider44
Explorer
May 16, 2013
The only time we get any smell is right after flushing if we have been in a stretch of very hot days. We use Happy Camper in our tank on average of once a month.
bthomforde
Explorer
May 16, 2013
Been full timming for over 5 years, don't use any chemicals, just water, the only time we get any smell is in HOT weather, then we just dump more often.

we don't use anti-bacterial soaps and try not to put anything down the drains that will kill the needed bacteria.
Son_of_Norway
Explorer
May 16, 2013
Having a helper pour some water down the vent stack while you check around the bathroom and the blackwater tank can help you locate a leak in the vent. You should also check the pipe from the flange down into the tank. Mine was cracked at the top of the tank and finding that cured my odor problem. Good luck with your repairs.

Miles