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**Stefrobrts** · 06-29-2003, 06:42 PM

Here's a rather delicate questions - how long can an average person go before you have to empty your black tank (we can be generic, I don't want to get too personal)? I ask because We arrived at camp early Friday afternoon with it empty, and by Sunday morning it was full. The black tank is supposed to be 18 gallons on the Caravel, but I am tempted to go out with a gallon jug and pour water in until it's full to check that, because I can't imagine we each produced 9 gallons of waste in a day and a half! If we're just over-acheivers, I guess we just have to live with that, but mostly I'm worried that the tank isn't as big as claimed, or water is leaking into the tank and filling it up when it's not being used. For this reason we try to keep the water pump off when we aren't using it. Or could there be some other mystery reason for the tank filling up fast?

j54mark · 06-29-2003, 07:24 PM

We (two adults) have a 30 gal. black tank and by being generous with the flushing are able to get it half full in four days. I try to get the black tank at least that full before dumping.

Mark

Pick · 06-29-2003, 07:52 PM

We can fill ours in 2 days and 3 nights. I always fill it with about 5 gallons after emptying it, so that leaves 12 gallons. We use lots of water. I don't want to mess with the "black pyramid"

**jcanavera** · 06-29-2003, 08:37 PM

We have gone 5 days with our 39 gallon black water tank and even then when we decided to do the big flush we added additional water to get it full. Two adults, no kids.

Jack

Pahaska · 06-29-2003, 09:16 PM

We have a 21 gallon tank and 48 hours in the trailer (2 nights) filled it about 35% this weekend. I added water to get it up to 50% before dumping.

I have more problems with the gray tank since my wife can't seem to grasp conserving water. She can fill the sink to wash two dishes and four pieces of cutlery. For that reason, I try to get to the dishes before her.

RoadKingMoe · 06-29-2003, 09:48 PM

We (two adults) also start out with 4-5 gallons of water to prevent the black pyramid from building up. In 5-6 days, the 39 gallon tank looked to be maybe half full. I added water before dumping.

Safari Tim · 06-29-2003, 10:22 PM

Three of us fill ours up in about 48 hours. Its only like 12 gallons I think.

I made the mistake of not dumping it until full, where the toilet would not flush. Went outside and found *stuff* leak out all over the place out of the underbelly skin.

Now I am sure to dump every moring of evening just in case, until I can figure out what it is.

We always get full hookups.

**Stefrobrts** · 06-29-2003, 10:41 PM

Well, we don't add any water to begin with, and use water very sparingly while flushing, so I'm surprised that ours fills up so fast. I guess I'll go try and figure out exactly how much it holds, then decide what to do from there. All I know is that I emptied it before we parked Friday afternoon, and by Saturday night the liquid was backing up the toilet hole (as in, I pushed down the foot pedal and I could see the water several inches below it). Who knows, maybe it needs a good cleaning (yuk!).

Either way I'd like to figure it out soon, we have two boondocking long-weekends planned for July, and if we fill up the black tank while we're out, there's no dumpstations anywhere near where we'll be!

RoadKingMoe · 06-30-2003, 07:06 AM

It's normal to see black stuff as the tank fills. It's a nasty job, but I'd have someone hold the valve open while I used a [disposable] yard stick to find the distance from the bottom of the tank to the top. Check with a flashlight to see where the top of the tank really is. It may be a bit below the joint where the toilet joins the tank. That way, you'll have a better idea of how full it is when you eyeball it in the future.

Chas · 06-30-2003, 08:27 AM

Quote:

Originally posted by Stefrobrts
Well, we don't add any water to begin with, and use water very sparingly while flushing, so I'm surprised that ours fills up so fast.

Definitely sounds like a "black pyramid syndrome". You must add water or else the golden bricks will stack right up exactly where they fall, creating a massive plug that blocks off the remainder of the tank. Yes, it is a bother to have to remember to fill with several gallons of water before use but it must be done.

Chas

RoadKingMoe · 06-30-2003, 08:56 AM

Chas is right. Without sufficient water, the "bricks" will literally cement themselves to the tank and to each other, and that can reduce tank capacity. If that's the case, I'd fill the tank with 5 gallon pails of warm water from the house and add a dose of Rid-X. After it sat full for a coupla weeks, then dump it and spray it out good with one of those wands that goes into the tank from the toilet. If you have "the pyramid," the yardstick is going to find it.

**Stefrobrts** · 06-30-2003, 11:14 AM

Well, I went out and measured gallon jugs into the potty until the tank was full, and only got in about 6 1/2 gallons! I rechecked the manual, and the tank is supposed to be 12 gallons, so I guess a little over half my tank capacity is gone. No wonder it filled up so fast!

Guys, I was only not using much water to flush with because it was filling up so darn fast. This is only our third weekend out in the trailer, and like I said, even with very little water it was full in a day. Same thing on our first trip. Luckily on our second trip we were able to dump every day.

Well, I guess there had to be something on it that needed work. So I guess I'll look into cleaning it. Good thing there's a dump station at the park across the street. This whole topic is just so YUCK! So what's better, using Rid-X or doing the ice cube thing? Or both together for maximum scrubbing action :-)

sash · 07-29-2022, 08:48 AM

Quote:

Originally Posted by Pahaska

We have a 21 gallon tank and 48 hours in the trailer (2 nights) filled it about 35% this weekend. I added water to get it up to 50% before dumping.

I have more problems with the gray tank since my wife can't seem to grasp conserving water. She can fill the sink to wash two dishes and four pieces of cutlery. For that reason, I try to get to the dishes before her.

Sounds like your wife is a brilliant strategist.

John Ware · 07-29-2022, 09:12 AM

Quote:

Originally Posted by sash

Sounds like your wife is a brilliant strategist.

I was thinking the same thing.

foobar · 07-29-2022, 09:32 AM

Folks are calling it the black pyramid, but it's really more appropriate to call it the "toilet paper pyramid of death"

Having lived in a 21ft travel trailer for 5 years during my undergrad college years, I am quite familiar with the pyramid of death. Didn't take me long to figure out that leaving the black tank flush valve open all the time was a bad idea.

The cure for the pyramid of death is unpleasant as it usually involves manually inserting something stiff and "L-shaped" into the tank from above via the toilet drain pipe and then repetitively filling the tank and manually swishing the rod around until the pyramid is no longer visible using a flashlight when the tank is empty.

Some sort of positive pressure face mask (scuba tank with respirator???) is handy unless you don't have a strong sense of smell.

Best of luck to you ....