Road trip: how often to dump tanks?

[Pat & Pete]

Some folks are simply lazy and use convenience as an excuse . I do the same , when it's convenient .

As for what might crawl up the sewer line , cockroaches for one . Some I've seen in a city park sewer that were an inch and a half long . Guaranteed , they don't mind running up a sticky , stinky hose . 

I just don't need/want that kind of aggravation/trouble . 

Anyway , you're gonna do what ever it is you're gonna do . Hopefully you catch every thing on sale .

[Ray,IN]

I have always traveled with a full  fresh water tank, JIC we unexpectedly dry camp that night, or one of us have an "accident" and require a shower..We're old ya'know. The choice/ability to do this totally depends upon the actual carrying capacity of your RV. Trying to save weight just in hope of a smidge better fuel mileage does not help mileage enough to calculate.

When It is convenient I will empty the black tank(regardless of amount) and use the tank flush feature to insure no solids remain, again JIC.

As to the gray tank, occasionally DW will start a load of clothes just before we depart, and it's finished when we arrive at the next stop. Out gray tank will hold 2 loads of wash water with enough space left to hold the water of washing hands and dishes,  etc.

Matter of fact, our MH drives and handles better with full fresh water and full fuel tank.

 

[Pat & Pete]

11 hours ago, Ray,IN said:

 

Matter of fact, our MH drives and handles better with full fresh water and full fuel tank.

 

Same here .

[kb0zke]

Our Foretravel has decent-sized tanks, and we've gotten used to how long we can go before needing to fill/dump. When traveling I plan on dumping and filling when we arrive at a campground. One park we like has only electricity at the sites. You dump and fill at the dump station, which is conveniently located for people leaving, but is still possible for arrivals to get in and out.

Why not dump when leaving? I think that everything sloshing around gets it all mixed better, so that more stuff dumps out. Like others, we have a third valve, so the procedure is this: hook up the stinky slinky; open the third valve; open and immediately close the grey valve to check for leaks, poor connection, etc.; if all okay, dump black tank; leave black valve open and dump a bit of grey; repeat as often as necessary until no more brown water; close black valve and finish dumping grey tank. I wear disposable gloves for all of this. When everything is done and cleaned up, I throw the gloves away and hook up the fresh water hose.

You will work out your own system. Whatever you settle on, though, follow it every time. Don't let someone distract you while filling and dumping. We can all tell stories of what we've seen others do.

[George the greek]

I was boon docking recently I can usually go two and a half weeks before my black tank is almost full but grey tank is another story. one day I was thinking my grey tank was getting close( dang sensors seem to give false readings) after washing up and brushing teeth in sink I noticed grey water just starting to come up through the drain in shower. I hooked up hose and drained  some of the grey water into a 5 gallon bucket then went and found a dump site. First time it ever happened to me. I'm new enough that I'm still having firsts 

GtG 

[Kirk W]

34 minutes ago, George the greek said:

I noticed grey water just starting to come up through the drain in shower.

That is the absolute indication of a gray tank full condition. It is one of the things that for all RV folks either has happened or will happen. I have experienced that many times over the years. 

[Jinx & Wayne]

Lots of opinions. 

We have a solidly built rig with well attached tanks. I also have a flushing system for the black tank - When the tank is open I can attach a hose and spray the inside of the black tank.  This removes solids.

I do not leave the gray valve open when parked and attached to sewer. I dump black and then gray when either tank needs to be dumped.  I like to  be able to flush out the hose with gray water after dumping the black tank.  That way any drip when disconnecting is less pungent. Also there are solids in the liquid going into the gray tank, despite wiping everything before dishwashing.  My feeling is that leaving the gray valve open allows solids to build in that tank, too.

I like to get the trailer mostly ready for travel the night before a travel day.  I dump tanks the night before traveling.  I don't like the weight of an even half full tank (200#). By the time we leave the next day there is a small amount of liquid and solids in the tanks.  I like to have that slosh around in the tanks when traveling.  About once per month on a travel day I dissolve a cup of borax in three gallons of water and dump it in the tanks before travel.  I then dump in 1/2 cup of dawn dish detergent. I do this for each tank.  When we next stop and hook up to sewer I immediately dump. This appears to remove buildup.  When I first started doing it I got a lot of fatty chunks out of the gray tank.  After about six months of this I don't see many solids. Since the rig was used I suspect that was the old buildup.  I haven't looked so this is just a suspicion now. Some folks have said the detergent can foam up through the sewer/pipes.  I haven't had this happen

As for dump frequency my limiting factor seems to be black water.  We go five days comfortably for two.  Somewhere in day six the tank will burp when flushed.  That is a sign that immediate dumping is needed.  If you don't dump then the vent can be blocked and the smell can get pretty strong.

After dumping the tanks I flush two bowls full of water down the black tank so there is always some liquid in it. I also add a scoop of RV-Digest-It enzyme to each tank after a dump.

Wayne & Jinx
2017 F-350 diesel, dually
2006 Carriage Carri-Lite 36KSQ

 

[RV_]

On 8/15/2020 at 9:26 AM, Bill Joyce said:

We were fulltimers for 15 years and are now parttimers and we leave the grey tank valve open until a couple days before we dump the black tank.  No problems.

We did as Bill does. I would fill the gray over the last two days and add a little bit of dish washing detergent to the black tank a couple of days before we would leave too.  After backflushing I'd add more water, maybe 5 gallons to the black and once in a while some with detergent to the gray to knock off any grease buildup. We used 2 ply regular TP and plenty of water and flushed the TP too. 

I don't know why a water bug or frog coming up the sewer line is freaking some out. I had two baby frogs and the occasional big water bug get in our regular home toilet in Louisiana. You are actually less likely to get critters coming up your lines.

I kept the gray open because for more than a few days I would forget and it would overflow into my shower when I was taking one! The gray stinks too so I preferred leaving them open. See the way RV toilets are made to keep the smells in the tank and vent to outside on the roof, No critters can come up when you flush as the water would carry them back into the tank, and the black is closed until I am ready to dump.

I don't want to spend big bucks over time hauling around an additional 300-500 pounds of water affecting my fuel costs. And I like enough water for the dog and to wash up for meals on the road, but only a few gallons. YMMV

Safe Travels!

Edited August 21, 2021 by RV_

[RV_]

3 hours ago, Jinx & Wayne said:

As for dump frequency my limiting factor seems to be black water.  We go five days comfortably for two.  Somewhere in day six the tank will burp when flushed.  That is a sign that immediate dumping is needed.  If you don't dump then the vent can be blocked and the smell can get pretty strong.

 

I forgot the burp indicator, I used that more than the sensors for my black dump frequency. This assumes your black tank vent is installed properly. Separate discussion. Whatever works for each is fine as long as they don't cause clogs and dried material by leaving the black tank open while in use.

[bruce t]

FWIW we dump on arrival at a park. The road movement sees to the 'lumps' and everything dumps fine. 

If weights an issue then I would be worried about the rigs overall capacity.

[lappir]

I have converted to putting nothing solid into the holding tanks, grey or black. (There are various methods). I tried leaving my two grey tanks and single black tank open at my current location and it seemed to work fine, but then it got hot and very dry and I would notice an ammonia odor at times. I have since gone back to keeping the gray tanks closed and did a "P" trap in my black tank hose. When the grey tanks are full I dump and one of the grey tanks uses the same outlet as the black so it flushes out the black tank when it's emptying, especially when it's completely full. Since I no longer have solids to worry about I have used the garden hose outlet on the cap for the kitchen grey and a 2 inch clamp on connector for the bathroom combo of grey/black. 

I travel single and can go for many weeks before having to empty, especially if I "Need" to.  Spent a whole summer more than once on a farm in Iowa where I pulled in with an empty Black tank and left with it full in the fall. The second year of doing I was starting to get worried and started the no solids activities and have adopted them for ever now I think. 

Each of us have reasons for how, when and where we do things. I will have to try the borax and dawn on of these days and attach a clear section to my hoses to see what comes out from my next trip. 

 

Rod 

[RV_]

12 hours ago, lappir said:

Each of us have reasons for how, when and where we do things. I will have to try the borax and dawn on of these days and attach a clear section to my hoses to see what comes out from my next trip.

Rod 

 

Yeppers Rod! One size fits all - of that one size!