Determining tank capacities.

[mwemaxxowner]

I'm starting to look at portable dump tanks for stays where there is no sewer connection on site. I looked up the specs on my camper on the Keystone website, and it listed me as having 24 gallons black tank capacity and 60 gallons of grey water.

What in curious about, is whether it's reasonable to assume that that is a 50/50 split with my galley tank and my bathroom grey water? Is there a placard I may find somewhere that tells me? I want a large enough portable tank so that any time I want to dump a full tank I can dump the whole thing at once.

[chuckster57]

The 60 gal of gray would include both gray tanks. So it would appear that all 3 tanks are about 30 gallons each. A 30 gallon tote would take all the contents of one tank.

[mwemaxxowner]

I know it includes both tanks, which was the reason for my question. Do we know it is a 30/30 split, or is that just an assumption? Not, 35/25, etc. I don't want it to get full then have 5 more gallons waiting for me to unhook the hose. (Yikes!)

[chuckster57]

You can do one of two things to check. Pour 5 gals at a time from a bucket, or fill the tanks and drain into a 5 gallon bucket. You’ll know the exact amount one way or the other.

We have had customers fill the tanks and measure with a bucket during walkthrough.

[mwemaxxowner]

I was just hoping there was a way to look ut up, or if perhaps somebody knew that Keystone always makes them both the same size or something. Or of maybe there was a placard somewhere that lists that information that I haven't found.

5 gallons at a time sounds like a pretty darn good idea though.

[uavpilotmk]

We have a 36 gallon dump tank and it’s about one man can handle by himself. It can sometimes be a chore getting the tank to your tow vehicle to bring it to the dump station to empty. Think about it. 36 gallons x 8lbs per gallon minimum = 288 lbs.

[mwemaxxowner]

I would like to think all I need is 30 gallons. I spend a lot of time intentionally dragging heavy things around for fun. Lol. I call it "training".

Mostly, the smaller I get the cheaper it will be, so no need for several reasons to get one larger than I need. But at the same time I don't want to limit my dump capacity and have to dump more often.

[chuckster57]

I have yet to see any placard or label that lists tank capacities for a specific unit. The tank itself may have capacity molded into the label but that means opening up the underbelly. And of course when you look up the specs on line there is a disclaimer at the bottom of the page:

“Subject to change without notice”.

[mwemaxxowner]

Sounds like a bucket it is! [emoji2361]

[mwemaxxowner]

This is all I've been able to find, which was better than nothing. I gave considered contacting Keystone, but when I did so for assistance with keys they just referred me to a dealership.

[uavpilotmk]

Originally Posted by mwemaxxowner

I would like to think all I need is 30 gallons. I spend a lot of time intentionally dragging heavy things around for fun. Lol. I call it "training".

Mostly, the smaller I get the cheaper it will be, so no need for several reasons to get one larger than I need. But at the same time I don't want to limit my dump capacity and have to dump more often.

I think you just answered your own question. LOL.

[mwemaxxowner]

Originally Posted by uavpilotmk

I think you just answered your own question. LOL.

I mean, that's assuming neither of my grey tanks are over 30 gallons. Lol

[JRTJH]

Consider that gray tanks, unlike black tanks, can be partially emptied without concern for "fouling the tank slide valve".... In other words, there's nothing in a gray tank contents that would get caught in the valve and make it stop sealing/working to close the tank. Think toilet paper, etc that, if the slide valve is pushed closed while that "stuff" is passing through the valve and is pushed into the rubber seal cavity, you've got a PROBLEM !!!

That won't happen with gray tank contents. So, if you want, you can empty a 45 gallon gray tank with a 10 gallon "blue tank"... just open the slide valve, fill the portable container, and when it's full, close the slide valve, go empty the portable tank, return and repeat as necessary....

Your comments: "Mostly, the smaller I get the cheaper it will be, so no need for several reasons to get one larger than I need. But at the same time I don't want to limit my dump capacity and have to dump more often."

What you're saying, from the way I read it is that you don't want to buy a bigger tank but you also don't want to make multiple trips to dump the smaller tank.... Looks like you're going to have to choose one or the other, or, probably a better choice, get the largest tank that fits your physical abilitiy to "manhandle" and also fits the space you have to store it for travel. It doesn't do much good to have a "one trip tank" if it won't fit in a space so you can take it with you and it doesn't do much good to buy an "affordable" 3 gallon portable tank" (when a 5 gallon bucket would do a better job).

I know the above goes to both the "too big" and the "too small" extremes. Each RV'er needs to compromise to fit both their needs and their ability to move/transport/store their choice of portable tanks.... That's why the come in multiple styles and sizes.

Rather than just focus on "how big is my "gray tank", you might also want to consider, "Where will I store this tank when I'm travelling and how easily will I be able to pull it around the campsite and transport it to the dump station?"

[mwemaxxowner]

You're exactly right. I don't want to spend substantially more than I NEED to on a portable tank, but I don't want to essentially limit my grey tank capacity because I can't dump all of it at once. Thereby reducing the time I can go between dumps. I'm also not sure what sort of mess I could encounter if I fail to close the tank valve in time once the portable tank is full. Just for grey water though I know that wouldn't be a huge problem if I spill the contents of the sewer hose.

I don't think I need to choose one or the other, I like the suggestion to just use a 5 gallon bucket and measure it myself. Seems a little nutty to have to resort to that just to know the sizes of the tanks installed on a camper, but hey what else can ya do!? [emoji4]

I would say that I'll just do that using the tub as my drain. Should be the easiest way.

5 or 10 more gallons isn't going to make it break my ability to drag the tank to my truck to pull to the dump station, and the extra effort is well worth extending the time between dumping for me. Same goes for storing the tank.

[travelin texans]

Originally Posted by mwemaxxowner

This is all I've been able to find, which was better than nothing. I gave considered contacting Keystone, but when I did so for assistance with keys they just referred me to a dealership. Attachment 22936

To add to the confusion that list states "LPG-40", that doesn't mean you have 40 gallons, but rather 2-20lb bottles = 10 gallons or 1-40lb = 9+ gallons.
From experience with my "little blue buddy" make yourself a 3" hose just long enough the connect to the portable tank with no sag, that will save a lot of mess. Believe me it goes into that tank A LOT faster than you can stop it.

[mwemaxxowner]

I assumed what that meant was 40 lbs, but it's cool to know what that equates to in gallons.

It actually had two 30lb tanks when I bought it. They were too old to refill, so I have two 20 lb tanks on it now. I use very little propane.

[Roscommon48]

get a 'blue boy' and move on.

as for time before you dump, it will greatly depend on you. One person, and not many showers it could be weeks. black water will be weeks too.

[mwemaxxowner]

I know it depends on how quickly we go through water, but if I'm leaving 5 or 10 gallons on the table, IMO that's a lot to sacrifice. Depending on the trip even one more day of use could be a big deal.

My question has been answered: no there is not apparently published information available on the individual grey tank capacities. I will measure myself, and know what size tank I need to buy. Thank you all.

[BadmanRick]

I have a 2011 bullet Premier 19fbpr it has a 30 gal gray and a 30 gal black. I have a barker 32 gal 4 wheelers tote tank. I normally run the gray open and when tank gets full I dump it. When my black tank gets full I empty it into the tote tank and empty it. Then use the gray to clean the blue tote tank.

[Firegod]

I am having the same issue with a brand new cougar. It's BS that somebody from Keystone can't tell us what size the tanks are that THEY installed.

All the dealer can stay is that "I think" they are equal size.