Question Grey tanks open

[Russellvh]

Newbie or inquisitive question.
I have read and noticed that some people choose to leave one of the grey tanks drain open when parked with full hookups. I believe the theory is they will need to dump less often.
My position is that when I dump my black tank I would like to have as much grey water as possible to “flush” the lines.
Is this just a personal choice or am I thinking this too much ? My mind does seem to wander when the outside temp is in 3 digits and I’m just sitting in the RV listening to both A/C s drone on.

 

[sheridany]

It’s really personal choice but I leave my grey closed as I want to flush hookup and the hose with as much grey water as I can. Of course there are a few that leave the grey open and hopefully they have a black tank rinse bib to fall back on. I use my black tank rinse after every black dump to keep things clean in the tank. The cleaner you keep your tanks the better your tank sensors will operate.

 

[Rich W.]

I subscribe to your theory. The more soapy grey water to flush out the stinky slinky the better. Sometimes I’ll take a shower or do a load of wash if I don't have enough grey water. Also I don’t want to have a connection to the sewer just standing open.

 

[Headhunter]

Same as the boys above. I always leave my gray water tank closed until read to dump. If full, and I had to dump before black for some reason I would take a shower or use my flush tank connection for about 10 minutes.

HH

 

[lordneeko]

When we are stay somewhere multiple days and likely taking multiple showers (in hot sweaty area of the world!) I keep the grey tank open all the way up to the afternoon of the day before we leave. This gives it plenty of time to fill up before I need to use it to dump the black tank.

 

[Buly]

The sewers are home of millions of roaches and rats. Leaving the valves open is an open invitation for some of them to relocate in your waste system.
Drowned rat in your tank can be a problem.
I always keep the valves closed until time to dump.

 

[redbaron]

I am a believer in treating gray like I do black. I have spent a long time trying to find the balance of the perfect dump sequence.

This graph and data point shows my current process.

Basically, if the gray tank is 65% and black is below 50,then dump gray.

As we approach higher levels hold gray longer.

My rules never dump black below 85, and never let a tank exceed 95%.

 

[J&JD]

Good grief! Forget the charts. There are normally just the two of us. Black is dumped every 4 days, consistently. Grey is left open until the day before the black is to be dumped so there is plenty of grey to flush the line after black is dumped. always flush black after dump.
Never had critters in grey in nearly 20 years of leaving it open, never. Never had black tank odor. Always treat black with a bit of Happy Camper. Grey treated about every 3rd dump with a bit of Happy Camper.

Motto: KISS

 

[redbaron]

Ha,charts just show historical view of how the water is managed.

Bottom line, I hook up, arm the system and then never think twice about it. Works just like a residential system, yet managed to best practices for an RV

 

[Buly]

One of the sewers critters
Sewer flies

 

[billnourse]

I don't leave grey tanks open. Invariably food particles and such are going to inadvertently get into the tank while doing dishes and such. I want any solids in the tank to stay in suspension as much as possible. This is why I add 5 or so gallons of water along with sanitizer to the black tank after I empty. I also use grey tank water to flush after emptying the black tank.

 

[DKRITTER]

I don't think there is A single correct answer to this. It lies much more in personal preference than anything else.

For us we choose to close the valves until either tank is almost full (80ish%) and then I usually dump both of them. A couple of things come into play like when are we leaving so I can flush the black tank.

 

["EZ"]

Redbaron you have WAY too much time on your hands!!!

 

[Bob K4TAX]

Although we have the stinky slinky connected between our TT and the sewer connection, we leave the valves closed until ready to dump. This allows the liquid in the black tank to carry out the solids, plus they slowly dissolve in the tank, which aids in flushing the tank. Then dump the grey tank to flush out the stinky slinky. This may take 2 or 3 days of collections with the 2 of us using the system. The bottom line is; WE DON'T LEAVE THE VALVES OPEN.

 

[redbaron]

Redbaron you have WAY too much time on your hands!!!

Its a combination of my hobby & my real job. Some of my best work has been derived from a hobby, which in turns creates the funds to continue my hobby.

 

[Bob K4TAX]

Did you write the code for the graphical interface or is it a package that was modified for the application? And did you design and build the control system?

 

[ehochuli85]

Its a combination of my hobby & my real job. Some of my best work has been derived from a hobby, which in turns creates the funds to continue my hobby.

My hobby is drinking and napping, and when I retired, my hobby became my full-time job.

I agree with the "keep them closed until you dump" theory. I'll also say, the best $200 I ever spent was on Electronic Dump Valves, so dumping gray or black is just a matter of pushing a button inside the coach!

 

[FL-JOE]

I have always left the gray open if hooked up for several nights. I also create an elbow that holds water in my stinkyslinky so no gasses from the sewer system can back up into my tanks. In addition to that I NEVER screw my sewer connection into the ground connection at the park. If something would happen and their system would backup I want it to simply knock my connection off and not flood my gray tank.

 

[redbaron]

Did you write the code for the graphical interface or is it a package that was modified for the application? And did you design and build the control system?

I am using Home Assistant for coach automation.

I designed the hardware that uses RV-C standard commands to operate the barker valves.

I wrote the software that runs on the hardware. This device works with any RVC controller that understands Tank dump commands and status.

In addition, I developed a separate piece of hardware / software that replaces the functionality of the LR-125/My Rozie. It runs on RPI4, and takes all the RVC messages, and decodes them to MQTT. It also accepts MQTT commands to push messages back to the RVC bus.

This is the basis of my integration with Home Assistant. All of my sensors, switches, etc are MQTT entities.

This is my base application screen on my PC. It also works on tablet/ phones, etc.
When I leave the coach (ie: my phone leaves) it will automatically lock the cargo doors and entry door, arm the Blink Camera's, and lower the shades. It also automatically turns off the water supply outside if I have it armed.

When I return, it will automatically unlock, and raise the night shades if it is still daylight. If it is dark, it will automatically turn on the exterior lights, and all interior lights, while enabling the water supply again. It will also disable the blink camera system.

All of this automation is pure Home Assistant. Nothing special. Tons of integration options. The only thing special is my hardware and software to control RV-C to MQTT and to operate devices.

This is the environment page:

This is really only useful for coaches that have a true RV-C system. The KIB system would work, and I have added some KIB to MQTT status and command entities, but KIB is so darn picky and unstable that it requires sending a message multiple times in hope that it does not get lost. My family loves the RV-C component operations, but they do not like the KIB entities (at least not yet).

I am working on a way to improve reliability, but it may entail just replacing some of the KIB relays with Sonoff Relays.

I have already added shade controllers to the front day & night shades, as those are manual on my coach, where as every other shade is automated. I made the front cockpit part of the KIB "Living Room" group, so that it operates with that group. The only one I left separate was the door shade, as I don't want that down when we are going in and out of the coach.

 

["EZ"]

Reminds me of an episode of Big Bang Theory............... You computer Geeks are so cool. Love the technology.