Pre-fill water in blackwater tank?

Always put clean water into your black tank right after dumping> How much depends on the size of your black tank but I have read 10% as a rule of thumb. So if you have a 40 gallon black tank put four gallons. Water is good for your black tank to keep it and anything left in it from drying out and clogging it - you cannot add too much water.

Bobbo wrote:
The gray tank smells as bad as the black tank. If either AAV fails, you will have odors.

That's what I thought. He specifically said black tank odors though.

lanerd wrote:
When you drain water out of your RV's sink the draining water creates suction (vacuum effect) on the valve which then opens and allows air in the pipe which in turn allows the water to drain freely. When the water is done draining the valve is suppose to close tightly and seal out any sewer smell smell from coming in the RV. The valve is part of the venting system for both tanks.

Hope this helps

Ron

AAVs (Air Admittance Valves) are installed 'downstream' of 'P' traps on sinks/shower drain lines.
They are there to allow air into drain line when draining grey tank so that the suction created doesn't suck 'P' traps dry.
Only time an AAV would be associated with a black tank is when a bathroom sink drains to that black tank. Otherwise only on grey tanks.

Wishbone51 wrote:

lanerd wrote:
Typically, the most common reason for black tank odors in the interior of an rv is due to a malfunctioned Air Admittance Valve (AAV) that is located under a sink (kit or bath or both)

What does the AAV have to do with the black tank? I thought it just admitted air to help sinks drain to the grey tank. I know that some bathroom sinks go to the black tank, but the kitchen?

The gray tank smells as bad as the black tank. If either AAV fails, you will have odors.

When you drain water out of your RV's sink the draining water creates suction (vacuum effect) on the valve which then opens and allows air in the pipe which in turn allows the water to drain freely. When the water is done draining the valve is suppose to close tightly and seal out any sewer smell smell from coming in the RV. The valve is part of the venting system for both tanks.

Hope this helps

Ron

for those who have problems with odors from the chemicals, just use happy camper in the tank. you will have no odors from the tank of any kind

lanerd wrote:
Typically, the most common reason for black tank odors in the interior of an rv is due to a malfunctioned Air Admittance Valve (AAV) that is located under a sink (kit or bath or both)

What does the AAV have to do with the black tank? I thought it just admitted air to help sinks drain to the grey tank. I know that some bathroom sinks go to the black tank, but the kitchen?

Grandpere wrote:

Old-Biscuit wrote:
Camping season.......fill toilet bowl full and flush (2 times) after dumping/rinsing black tank. This keeps tank bottom wet so any poop doesn't dry out. Dried poop turns hard as concrete. Also with 2 toilet bowls in tank it is ready for use.

Winter/storage season.......drain/rinse tank thoroughly and then add some RV anti-freeze to keep tank bottom and dump valve seals wet. Water OK but anti-freeze eliminates freeze concerns


Tank additives....
Personally don't use them. Can't stand that 'chemical smell'.
When tank vents, seals, 'p' traps, AAVs work there is no smell inside rv except for that moment of flushing toilet, which tank chemicals does nothing for.
Use them if you want...it's your rv.
Has no effect on me

X2 except for the additives. We have used Thetford which does a great job on the smell. However this season we are going to try Walex BIO-11530 Bio-Pak Natural Holding Tank Deodorizer and Waste Digester. I am hoping this product will help with breaking up the toilet paper and also the solids plus handle the smell.

Also, when we dump we rinse the tank at least twice using the Camco Swivel Stik Rv Tank Rinser.

If your toilet does not go straight into the black tank there is a flexible version Camco 40074 Flexible Swivel Stik

Russ, with all due respect, if you have an odor that requires you to dump in chemicals to mask....you have a problem. Typically, the most common reason for black tank odors in the interior of an rv is due to a malfunctioned Air Admittance Valve (AAV) that is located under a sink (kit or bath or both). Locate, remove, and replace this valve and I bet your odors will disappear. There can be other reasons for interior black tank odor (clogged vent, poor seals, etc), but the AAV is typically the culprit.

Adding chemicals to your tank is just throwing your $$ down the toilet. Find the problem and fix it.

Good luck with this..

For the OP (mtnbbud), I too will add a couple of gallons of water back into my black tank immediately upon draining and flushing it. As mentioned, keeps the solids for solidifing. As for your sensors... what I do before each day of traveling, is after draining and refilling and draining again until nothing but clear water comes out; I will add a few gallons and also a cup of laundry detergent (I use Oxy Clean). When traveling, the back and forth movement of the rv will slosh around the soapy water and will "sometimes" clear the sensors of what may be clinging to them. Give it a shot and see if it helps.

Ron

I'm guessing a few gallons goes in after every dump. Not like it is some sort of exact thing. The trailer has a built in tank wash which gets run from before the black valve is opened till a little before the grey valve gets closed.

We don't waste time at the dump station. Don't dump every day either. More like every 4 days.

gbopp wrote:
Some use The Geo Method to help keep their tank clean.

I've been using The Geo Method for years and found it worked as well or better than any commercially available tank treatment products I had tried in the past, be they chemical or bacterial. However, near the end of last season I had the opportunity to try Walex Elemonate and Walex Porta-Pak in the grey & black tanks and really liked the results so this year I plan to use Geo just when servicing the tanks but prep the tanks for camping with these two Walex products.