Question about grey and black water tanks.

Hello all, thanks advance for the help. I have question about waste water tanks. I currently own pop but am thinking of upgrading to a travel trailer. It comes with bathroom and therefore has tanks. I've never used one before so I'm looking for some clarification.

If I'm at a campground that has full hookups and I connect the waste hose to the connection on the campsite does the waste water still collect in the tanks first or does it go directly into the site septic? Meaning do I still need to clean tanks after the trip if I use a direct hookup? And is there anything I should know beforehand about waste tanks from seasoned RVers?

Thanks again for the help.

Well you can do it both ways but most folks keep the valves closed to allow enough contents to build up in the tank that when they DUMP it DUMPS with force, flushing all the "Stuff" the tank.

First dump black, then close that valve and dump gray.

NOTE: There are a whole bunch of companies willing to sell you expensive and useless chemicals to put in the tank to prevent "Stink".. well I have found that "Stink" is more likely to come up out of the hole in the ground via an open valve than from the tanks on the RV.  So unless you always "Water trap" your lines (Not legal in some places,, well one that I knwo of ) keeping the valves closed is the best way to prevent that stink.  Have had "Stink" issues 3 times. once in a building, (The traps were dry) and twice when I forgot to close a valve.

Note, too, that even when you leave the valves open, the sewage path is still through the tanks. However, I wouldn't say you need to clean the tanks after use, in the sense of washing them, but you do need to dump them and ensure that you don't get a buildup of solids in the black tank. Generally using plenty of water for each flush and leaving its valve closed until it's half full or more will suffice.

Ok thanks. That clears things up. I wasn't sure if using a direct hookup would bypass the tanks. But if it passes thru anyway then it doesn't matter. And you say you don't need to wash the tanks after every trip? My wife suggested a "liquid only" rule for the toilet but I don't know if that's necessary.

Thanks for the info, i appreciate it.

Only using the toilet for liquids falls in the "obsessive" category in my mind. The waste tanks do not need to be "clean" in any normal sense of the word, just "cleaned out" through standard draining and flushing. You're paying good money for the facilities in the trailer. Why wouldn't you want to use them as intended?

The whole notion of "washing" a waste tank makes me chuckle. Rinse, maybe, but it certainly doesn't need washing.  Obviously you don't want any solids to accumulate in there, so a rush of water thru them is a good thing. For that reason, leave the black tank closed and let fluid accumulate, then, when it is mostly full, open the dump valve to let the contents run out with a whoosh! That will carry any undissolved stuff along with it. If adequate fresh water is available, you may want to run more in and repeat the process, but it's not strictly necessary. Some RVs have rinsing nozzles built in for this purpose.

The gray water tank also accumulates food scraps, hair & other greasy residue, whether the valve is left open or not. Therefore some people use the same procedure with gray water, i.e. leave the valve closed and dump when near full. However, for convenience many just leave the gray valve open much of the time, but close it up periodically to build up enough water for it to rinse itself. If you do that at the same time as the black tank gets dumped, the gray water will also flush any black water residue from the sewer hose.

There is an article in the forum Library on sewer dumping procedures:
http://www.rvforum.net/joomla/index.php?option=com_content&view=article&id=87:sewer-dumping-procedure&catid=41&Itemid=132

Gary RVer Emeritus said:

The whole notion of "washing" a waste tank makes me chuckle. Rinse, maybe, but it certainly doesn't need washing.  Obviously you don't want any solids to accumulate in there, so a rush of water thru them is a good thing. For that reason, leave the black tank closed and let fluid accumulate, then, when it is mostly full, open the dump valve to let the contents run out with a whoosh! That will carry any undissolved stuff along with it. If adequate fresh water is available, you may want to run more in and repeat the process, but it's not strictly necessary. Some RVs have rinsing nozzles built in for this purpose.

The gray water tank also accumulates food scraps, hair & other greasy residue, whether the valve is left open or not. Therefore some people use the same procedure with gray water, i.e. leave the valve closed and dump when near full. However, for convenience many just leave the gray valve open much of the time, but close it up periodically to build up enough water for it to rinse itself. If you do that at the same time as the black tank gets dumped, the gray water will also flush any black water residue from the sewer hose.

There is an article in the forum Library on sewer dumping procedures:
http://www.rvforum.net/joomla/index.php?option=com_content&view=article&id=87:sewer-dumping-procedure&catid=41&Itemid=132

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what to do if black water tank level sensors seem to have something on them? I just dumped our black water tank which was most likely 3/4 full and the sensors still indicate 3/4 full.  Anything I can do sitting here parked for next month?

decaturbob said:

what to do if black water tank level sensors seem to have something on them? I just dumped our black water tank which was most likely 3/4 full and the sensors still indicate 3/4 full.  Anything I can do sitting here parked for next month?

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Buy a waste tank flush wand, hook up a hose and stick it down the toilet into the black tank and blast away. Or do what many RV'ers do, and just look down the hole to see how full the tank is. On the other hand, I installed a SeeLevel II tank monitor system on our coach that uses external tank sensors that are much less effected by internal buildup.

Valterra Master Blaster Tank Wand

SeeLevel II 709 Tank Monitoring System

decaturbob said:

what to do if black water tank level sensors seem to have something on them? I just dumped our black water tank which was most likely 3/4 full and the sensors still indicate 3/4 full.  Anything I can do sitting here parked for next month?

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There is plenty you can do.
I recommend you ignore it and move on with your life. It's not worth the trouble.  You don't really need it.  Especially the black.

To wit:

When I was rebuilding my trailer I had to remove the tanks.  My black water tank sensors were always reading 1/3 to 2/3 full when empty.  So I took the opportunity to completely wash the tank.  After everything was back together the tank read empty.....yes!   I filled it and drained it twice.  Everything indicated correctly along the way.....yes!.  Took my first test trip since the rebuild, and setup camp.  Not one drop of liquid had since been placed in the tank.......2/3 full . @#%#@#?!

Angry_mammoth said:

My wife suggested a "liquid only" rule for the toilet but I don't know if that's necessary.

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No need for that, depending on how big your tanks are... she might just be grossed out by the thought of that tank sitting there full of crud (literally), but you'll forget about it after awhile.    And actually, the idea of leaving the tank valves closed (until ready to dump) keeps solids mixed with liquids and helps the "good" bacterial action liquefy everything so it'll flush out when it's time. 

RV black tanks work in a similar principle to home septic systems, if your home has ever had one of those.  Bottom layer of contents is solids, top layer is liquids.  You want to use plenty of water when flushing solids down an RV toilet, so there is lots of liquid to force everything out when dumping the tank.  The water also provides an odor barrier.  No chemicals should be needed in the tanks, although you'll see them on shelves anywhere RV products are sold.

decaturbob said:

what to do if black water tank level sensors seem to have something on them? I just dumped our black water tank which was most likely 3/4 full and the sensors still indicate 3/4 full.  Anything I can do sitting here parked for next month?

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Not really.  After using your system for awhile, you'll have a pretty good idea on how often you need to dump the tanks... with or without working sensors.  If your toilet has a straight drop into the black tank, you can always open up the toilet valve and take a look with a flashlight to see where the water level is at.  As mentioned, even if you get the sensors working it won't be long before they're "gunked up" again and reading "Full" when really not.  There are aftermarket sensors or "see through" tank level indicators you can buy, but I don't know how well they work or if they're worth the money/effort to install.

There are aftermarket sensors or "see through" tank level indicators you can buy, but I don't know how well they work or if they're worth the money/effort to install.

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I can't comment on any others, but the See Level sensors are excellent, even giving level to the nearest four or five percent, rather than 1/3, 2/3, etc. They're an electronic strip stuck to the outside of the tank, rather than "nails" poked through the sides of the tank, so they don't get crud on them. They're worth it to me.

As far as a "liquids only" rule goes....I think the OP's DW will soon find out that being able to perch upon her own throne when the time comes, rather than wandering down to whatever public facilities are available at the park or campground, is one of the great advantages to having a travel trailer.

Exactly. I can't figure out for the life of me why people have a problem using the toilet for what it was designed for. #1,#2, wipe with whatever toilet paper you like, use a sensible amount of water and flush it down. No problems, no worries.

Patnsuzanne said:

As far as a "liquids only" rule goes....I think the OP's DW will soon find out that being able to perch upon her own throne when the time comes, rather than wandering down to whatever public facilities are available at the park or campground, is one of the great advantages to having a travel trailer.

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A comment you'll see around here regarding one of the many benefits of RV ownership (versus hotels for instance) for travel... you know what happened in the bed, and you know who sat on the toilet. 

Thanks all for the replies. I think the liquid only suggestion was because we didn't fully understand how they work. Now knowing more it seems a non issue. We were under the impression the tanks needed to cleaned after each trip. Again you've cleared things up.

kdbgoat said:

Exactly. I can't figure out for the life of me why people have a problem using the toilet for what it was designed for. #1,#2, wipe with whatever toilet paper you like, use a sensible amount of water and flush it down. No problems, no worries.

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^^The BOTTOM line. (yes,  Pun intendd) : )

The "liquid only" rule is rubbish.  I can't imagine having a great RV with all the facilities and not using them.  I seldom use the campground bathrooms because I like using my own!

Many of us have a separate hose that is used for rinsing the toilet bowl itself.  Some RVs come equipped with same.  As long as you use enough water and a decent toilet paper that dissolves readily (something that says it's septic safe works just fine) you'll like having and using your own bathroom.

ArdraF

ArdraF said:

The "liquid only" rule is rubbish.  I can't imagine having a great RV with all the facilities and not using them.  I seldom use the campground bathrooms because I like using my own!

Many of us have a separate hose that is used for rinsing the toilet bowl itself.  Some RVs come equipped with same.  As long as you use enough water and a decent toilet paper that dissolves readily (something that says it's septic safe works just fine) you'll like having and using your own bathroom.

ArdraF

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If you think the "liquid only" rule is rubbish, you should have met a former neighbor of mine. He still had the factory tape seal on the toilet and plastic on the carpets in the 5'ver he'd bought new about 10 years previously. He claimed he didn't want to hurt the trade-in value...  :

NY_Dutch said:

If you think the "liquid only" rule is rubbish, you should have met a former neighbor of mine. He still had the factory tape seal on the toilet and plastic on the carpets in the 5'ver he'd bought new about 10 years previously. He claimed he didn't want to hurt the trade-in value...  :

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I'm afraid he probably learned that lesson the hard way, if and when he finally traded in the rig!

scottydl said:

I'm afraid he probably learned that lesson the hard way, if and when he finally traded in the rig!

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As far as I know he still has the trailer. I'm sure the extra $20 he gets at trade in will make it all worthwhile though.