Black water into gray water

[Kafn8td]

At the risk of making some heads spin and starting a war, I have a question. My shower drains into my black water tank - yes it was designed that way - yes it is RVIA approved etc.

The issue is, my gray water never fills up and the black fills up quickly. If it was the other way around, I would buy an equalizer (twist on waste vale)and when getting full equalize the tanks.

However, since it is the other way around, is there any reason not to do it? They are both cesspools of bacteria so I really can't think of a reason not to do it.

[K3WE]

The gray tank almost always fills faster than the black- AND sometimes there are problems with black tanks clogging due to a lack of water...Thus as someone posted before- they sometimes run the bathroom sink to the black tank to help with that.

Speaking only as an outsider- it does seem "bad planning" to have the shower supplement the black tank- showers can generate a LOT of water...

...additionally, when the gray fills first- there's a slight psychological advantage to running from the gray to the black as opposed to the opposite.

Some folks have gotten quite mental over the thought of black water entering the gray side- or even being briefly connected together with those valves...I agree with the post immediately above that mother nature generates beautiful-biodegrading-but-potentially-pathogenic bugs in both gray AND black water.

[Effy]

A lot of folks link the 2. Nothing wrong with it at all provided you take precautions on a backup should they get full. As another poster said, grey can be just as bad if not worse than black. I would do it on mine, but the places that they sit are just too cumbersome to tie together.

[tvman44]

I don't see any problem with what you want to do.

[Kafn8td]

lawrosa, that is the newer manual. I have an '11 and it's not the same.

[lawrosa]

Yes per your trailer manufacturer that is not correct... page 57. It should be seperate..

http://www.cruiserrv.com/images/downloads/Cruiser%20RV%20Owners%20Manual.pdf

[LarryJM]

lawrosa wrote:
Really thats odd.. What make/model camper is it? I would like to reseach that..

But IMO I see no issue with what you propose other then the fact that the grey water discharge pipe is smaller diameter. So if waste moves to the gray side you may be more prone to clog issues...

Not only that, but I just don't think it's a good idea to mix normal sink waste with body waste. Now shower drainage might be as far as I would go in mixing the two. Other that the above pipe size consideration I'm not sure there is a real good technical reason one way or another.

Larry

[beemerphile1]

Kafn8td wrote:
...They are both cesspools of bacteria so I really can't think of a reason not to do it.

I agree and wouldn't hesitate to equalize like you are proposing.

I've never heard before of the shower being piped into the black. Sometimes the hand basin but never the shower.

I wouldn't want the tank to fill while I was in the shower and be standing ankle deep in poo water.

[Kafn8td]

Thanks Old-Biscuit. 1 for not telling me what a piece of******I own 😉 and 2 for giving real world experience. I will give it a trial run this weekend with water and see how it works.

[Old-Biscuit]

I have 3 waste tanks
Black Grey and a Galley.
All three drain thru same main drain line.
I permanently installed another drain valve on the common drain line.
With it closed I can shuttle waste water (it's all waste water and grey can smell just as bad if not worst then black) between tanks by opening the 3 individual tank valves.

I have 138 gallons of waste tank capacity :B
And I have never had a problem with any of the tanks/drain lines/blockage/pluggage etc.

I remember a time not so long ago that RV's only had ONE waste tank

Added benefit of the extra drain valve...no surprises when I remove drain cap :B

[Golden_HVAC]

The more I look at the Cruise RV website, the less I am liking the RV. The weight is very light, I guess that is good. I just hope that the frame is strong enough.

The furnace size is marginal. I have a 30,000 Btu furnace on my 30' Bounder, and while it does not need to run a long time each time it is on, the 20,000 Btu in this trailer will spend more time running than a 30,000 Btu one would. This is important for two reasons. It is noisy, making watching a DVD more difficult while the furnace runs. The 2 solutions is turn down the thermostat until the movie is over, or take a break while it is on, or turn it up really lound. The second reason is battery power. If my furnace needs to run 10 minutes every hour, yours would need to run 15 minutes due to it being 2/3 the size, and my RV also being about 30' long. The fan draws about 6 amps per hour, so I can run mine 6 hours for the same energy that yours will use up in 4 hours. Mine might run 10 minuets per hour and take 6 hours to use up 6 amp hours of power. Yours would run 15 minutes per hour, and use the same energy in 4 hours time (60 minutes run time, say from 9 pm to 1 am).

My next question is how large is the converter/charger? IF less than 45 amps, you will spend a long time running the generator to refill the battery. It is also more likely to overload or overheat a 30 amp converter than a 55 or 60 amp converter. Even though you "Can" get by with a 20 amp converter, charging from a generator would take a really long time. Fine if you plan on spending time in a lot of campgrounds (like some RV'ers do). Yet many who buy a toyhauler also want a RV capable of camping out in the desert, without hookups, perhaps only the battery to rely on,or a generator. So charging quickly is important.

So if they cut corners on things you do not see, such as the furnace capacity (causing it to run more minutes per hour than a larger unit would take to get the same job done) or more important (to me at least) converter capacity, I would stay away.

Fred.

[Kafn8td]

Good find, I didn't think to check the newer models. I know there is a lot of room around the gray tank, so I may be able to replace it with a bigger tank and plumb the shower to it. The black is hidden so I have to figure out how to get to it.

[Golden_HVAC]

Kafn8td wrote:
It is a 2011 Cruiser Fun Finder XT276 TH. I was told it was manufactured that way to help with the water to solids ratio.

edit - I didn't consider the different size pipes. I'll have to take a better look at it this weekend.

I was looking at the specs of the current model year XT276 and see that it has a 38 gallon black tank and 63 gallon grey tank.

http://www.cruiserrv.com/products/fun-finder-xtra/floorplans/item/xt-276

I can only wonder if they increased the grey tank size, and now have the shower drain into the grey tank?

I would rather recommend installing a new tank for the shower water, and avoid letting the shower water connect to the black tank, just in case it might overflow.

Tank-Depot.com is one place that sells new tanks. You would also need to figure out a way to support the tank, and relocate the plumbing lines. Then connect the new and factory grey tanks together, so they will drain at the same time.

I think that one of the main health reasons for keeping the black water out of the grey tank is that bacteria can crawl up the piping and end up in the kitchen sink. Much more difficult when the tanks are separated by a valve.

We had a recent E-Coli bacteria scare here in Portland OR recently and had to boil water for about 3 days - just a week ago. They say it could have been a bird that died in the 14,000,000 gallon open water reservoir, where the water 'should' is treated before entering the Portland water piping system.

E-Coli can move around through moist areas, such as the tubing in your water system.

Fred.

[Kafn8td]

Thanks for letting me know you will never buy a Cruiser Fred. Good thing there's choices.

[Golden_HVAC]

Hi,

Really nothing to do with the valve size, however the larger valve is handy to let through the clumps of toilet paper.

I personally would not want the shower connected to the black tank, as when the tank is 90% full and you are driving down a mountain road, you might get waste water out of the tank. Bad enough if the grey water ends up in the shower plan - but a real problem if it is some black water mixed in with it.

Back in the 60's most RV's had a combined tank of around 20 - 25 gallons, mostly due to the truck chassis limited to about 8,000 GVWR and the limited HP gas engines at the time - perhaps 90 HP was common. Some might have a 10 gallon black tank and no grey tank at all, or it might have a drain right onto the ground.

RIVA started requiring 2 tanks so that if you did overflow one tank into the shower pan, it would not be black water. I can not understand why this company would take a step so far backwards into allowing black water into the shower pan. Personally it would be a reason to never buy that brand RV.

Kinda like when I looked under one brand of RV back in 1994 and found the shower drain line went from the passenger side to a black pipe, under the driveshaft to the side of the grey water tank on the drivers side. At first I was thinking "I am being to critical" of this situation, however later I was thinking that "How stupid is this design?" When taking a left turn on a mountain road, water can come gushing out of the shower drain line if the tank was full, and water rushed to that side of the tank! And the black water tube under the driveshaft - that was silly enough too. . .

Anyway it is reason enough for me to not buy that brand. They should have designed the RV with a larger grey tank, and drain the shower into that. So no backups can end up getting black water into the shower pan, that is REALLY bad.

Fred.