I have read many threads that refer to the "black tank burps" as an indicator of when it's time to dump it. I, too, experience this and have begun using it as my indicator of dump time. My question is ... why does it do that? It's an interesting phenomenon, but I am wondering if anyone knows, or has a theory, on why this happens.
The Bear II said
02:16 PM Feb 23, 2017
theory only- The stuff in the black tank has reached a point where in order for new stuff to slide into the tank air needs to be displaced and since the toilet chute is the closest to where the stuff is depositing the burp occurs. Prior to being near full the air will release through the black tank vent so no burp up the toilet chute occurs.
RonC said
03:13 PM Feb 23, 2017
The Bear II wrote:
theory only- The stuff in the black tank has reached a point where in order for new stuff to slide into the tank air needs to be displaced and since the toilet chute is the closest to where the stuff is depositing the burp occurs. Prior to being near full the air will release through the black tank vent so no burp up the toilet chute occurs.
I hadn't thought of this before but I'm sure you are right about the air displacement required to accept the "load" (sorry, couldn't resist). What hadn't occurred to me was that, when full or near full, the vent pipe could become submerged and the air no longer has a place to go. Good thinking Bear!!
-- Edited by RonC on Thursday 23rd of February 2017 03:13:46 PM
Gpndavid said
05:22 PM Feb 23, 2017
I was waiting for Linda "The Toilet Whisperer" to reply, but can't hold it (pun intended). You guys figured it out. The toilet vents at the roof. The connector pipe is several inches below the bottom of the bowl. Once the vent connector is obscured, the only place for air to escape is the ball valve in the bowl. Howard and Linda explained the "burp" to us at a rally. When you hear that, you need to make dumping the black tank a top priority. On a related note, if you are back flushing your black tank and leave the dump valve closed, the tank will fill all the way up the vent pipe and you will have a small fountain coming out the top of your RV. Not as dramatic as Robin Williams portrayed in the movie "RV", but enough to get you some laughs from fellow RV'ers.
bjoyce said
09:01 AM Feb 24, 2017
Gpndavid wrote:
I was waiting for Linda "The Toilet Whisperer" to reply, but can't hold it (pun intended). You guys figured it out. The toilet vents at the roof. The connector pipe is several inches below the bottom of the bowl. Once the vent connector is obscured, the only place for air to escape is the ball valve in the bowl. Howard and Linda explained the "burp" to us at a rally. When you hear that, you need to make dumping the black tank a top priority. On a related note, if you are back flushing your black tank and leave the dump valve closed, the tank will fill all the way up the vent pipe and you will have a small fountain coming out the top of your RV. Not as dramatic as Robin Williams portrayed in the movie "RV", but enough to get you some laughs from fellow RV'ers.
This mostly happens when someone hooks up a hose to their black tank flush and forgets they did so or gets distracted.
Bruce and Robin said
09:26 AM Feb 24, 2017
To take this conversation to another level, what do you place in your black and/or gray tanks to help keep it broke down so that you empty your entire tank completely?
You read stuff on line and half is advertising a product, but what really works. I would say no chemicals from what I have read but what about products like Tech Tanks Rx or other types of organisms that break down the solids.
Give me the short version of the TP education. We are going to the Spring Rally in 2017, but unexpectedly are starting FT next week. That is what happens when you sell everything way before you thought and purchase an RV sooner than expected.
Thanks,
Linda said
09:32 AM Feb 24, 2017
Very Good David! It is wonderful to see that "The Toilet Whisperer" info stayed with you!
Howard said
09:49 AM Feb 24, 2017
Yes, as mentioned, the holding tanks are vented with a pipe going to the roof of the RV. This diagram is a good example.
Gases tend to build up in the holding tanks, and these vent pipes allow the gases to release. However, when the liquid in the black tank gets high enough to block off the vent pipe, the gases then have nowhere to go except between the tank and the pipe leading up to the toilet. When you flush the toilet, the gases release through the bowl causing the "burp".
As for the other issue, I just wanted to clarify that Bill's comment related only to the backflushing and not the "burp".
"On a related note, if you are back flushing your black tank and leave the dump valve closed, the tank will fill all the way up the vent pipe and you will have a small fountain coming out the top of your RV. Not as dramatic as Robin Williams portrayed in the movie "RV", but enough to get you some laughs from fellow RV'ers."
Bill's quote: "This mostly happens when someone hooks up a hose to their black tank flush and forgets they did so or gets distracted."
Though this next part should really be in a different thread, it's partially related.
"To take this conversation to another level, what do you place in your black and/or gray tanks to help keep it broke down so that you empty your entire tank completely? You read stuff on line and half is advertising a product, but what really works. I would say no chemicals from what I have read but what about products like Tech Tanks Rx or other types of organisms that break down the solids. Give me the short version of the TP education. We are going to the Spring Rally in 2017, but unexpectedly are starting FT next week. That is what happens when you sell everything way before you thought and purchase an RV sooner than expected."
As full-timers, we use nothing in our tanks as far as products go. You'll want to use plenty of water in your black tank, but always keep the black tank closed until it is nearly full. Never leave the black tank open while hooked up to a sewer connection - liquids drain out and solids build up and harden. As long as you are using plenty of water, the solids will break down naturally. If you still want to use a product, we recommend either "Happy Camper" or "Digest-It".
As for toilet paper, use something that is septic safe and passes the "swish" test. Take a few squares, put them in a container of water and swish them around. If they dissolve completely, you are good to go. If you are seeing toilet paper in your pipes when dumping, it's not the right kind - it should always dissolve. Not a bad idea to put a few gallons of water in the black tank after dumping to "charge" it and let it swish around in the tank while moving.
That's the short version. You'll learn more at the Rally. :)
Barbaraok said
09:52 AM Feb 24, 2017
Bruce & Robin,
The answer is water, water, everywhere. All you need is water. You provide the necessary bacteria to get things going (yes, the puns keep on coming) and biochemistry takes over. Plus, these are holding tanks, not septic tanks. As long as you use enough water, everything liquefies, and fluid mechanics takes over when you pull the dump handle. BTW - pouring some vinegar into the bowl and letting is sit until the next use, will help reduce calcium buildup on the ball seal. And a little baking soda is always good in any drain/holding tank to help buffer the water and reduce scale.
Barb
The Bear II said
09:56 AM Feb 24, 2017
To break down the "stuff" I have always used Thetford Aqua-Kem powder. The little bugs (enzymes) in it do a good job of breaking everything up.
It seems to last through several full tanks. I'm guessing the bugs are able to hold on to the side of the tank while the "stuff" is draining out....tee heee or should I say Tee Peee
Bruce and Robin said
10:13 AM Feb 24, 2017
Thanks everyone for the information! Again, this is an awesome site with great information.
Howard - See you in a few months, thank you for the feedback :)
NWescapee said
04:44 PM Feb 24, 2017
One note on products: So while some people really think Happy Camper is a good product (and it was heavily recommended at the Oregon rally a few years ago), we were told by people who run a business cleaning tanks that it's one of the worst products you can use. It actually causes calcification and you will end up with crystals in your tank.
Ask us how we know? We had the tanks professionally cleaned and it took twice as long as usual and they showed up the pile of calcified crystals they removed during the process. Since then we can extend our boondocking time without the need to empty the tanks as frequently. No more Happy Camper for us.
Barbaraok said
05:14 PM Feb 24, 2017
The Bear II wrote:
To break down the "stuff" I have always used Thetford Aqua-Kem powder. The little bugs (enzymes) in it do a good job of breaking everything up.
It seems to last through several full tanks. I'm guessing the bugs are able to hold on to the side of the tank while the "stuff" is draining out....tee heee or should I say Tee Peee
Not really. You would have the same results with just using plenty of water, the 'bugs' are bacteria from your gut, that is all that is required. You do not have a septic tank, but a holding tank. You don't need to digest the wastes, merely liquefy so that everything will move smoothly when you pull the dump handle. And yes, I really am a scientist.
RonC said
12:01 PM Feb 25, 2017
First ... thanks for all the feedback and discussion ... awesome. We have been using a product made by Walex called "Bio Pack" ... it's supposed to aid in breaking down the TP and Bio stuff, and to be honest, I have been pretty happy with it. However, when long termers like the Payne's and the O'Keeffe's say "just use a lot of water" and that they don't use any "additives" ... I think I'll change my plan. Their collective 25 plus years of experience trumps my 4 months.
Barbaraok said
01:59 PM Feb 25, 2017
Do test your TP in a jar of water. Shake a couple of sheets in the jar full of water and see if they start to dissolve. If they don't, change brands. That's an easy way to make sure you keep everything moving, so to speak.
Terry and Jo said
01:05 PM Feb 27, 2017
Jo and I have been full-time living in our fifth wheel now for almost 6 years. We never add any chemicals.
As for toilet paper, we used to use Angel Soft, but I've since changed to Scotts "septic safe" TP. Back when I used Angel Soft, I could see bits of paper floating by in the clear plastic sewer extension, even after multiple "cycles." (To me, a "cycle" is after flushing the tank for several minutes, I would close the black tank valve for 2 1/2 minutes and then re-open for 2 1/2 minutes.) After changing over to Scotts, I never see the bits of paper floating by, even after only one cycle.
I have read many threads that refer to the "black tank burps" as an indicator of when it's time to dump it. I, too, experience this and have begun using it as my indicator of dump time. My question is ... why does it do that? It's an interesting phenomenon, but I am wondering if anyone knows, or has a theory, on why this happens.
I hadn't thought of this before but I'm sure you are right about the air displacement required to accept the "load" (sorry, couldn't resist). What hadn't occurred to me was that, when full or near full, the vent pipe could become submerged and the air no longer has a place to go. Good thinking Bear!!
-- Edited by RonC on Thursday 23rd of February 2017 03:13:46 PM
This mostly happens when someone hooks up a hose to their black tank flush and forgets they did so or gets distracted.
You read stuff on line and half is advertising a product, but what really works. I would say no chemicals from what I have read but what about products like Tech Tanks Rx or other types of organisms that break down the solids.
Give me the short version of the TP education. We are going to the Spring Rally in 2017, but unexpectedly are starting FT next week. That is what happens when you sell everything way before you thought and purchase an RV sooner than expected.
Thanks,
Very Good David! It is wonderful to see that "The Toilet Whisperer" info stayed with you!
Yes, as mentioned, the holding tanks are vented with a pipe going to the roof of the RV. This diagram is a good example.
Gases tend to build up in the holding tanks, and these vent pipes allow the gases to release. However, when the liquid in the black tank gets high enough to block off the vent pipe, the gases then have nowhere to go except between the tank and the pipe leading up to the toilet. When you flush the toilet, the gases release through the bowl causing the "burp".
As for the other issue, I just wanted to clarify that Bill's comment related only to the backflushing and not the "burp".
Bill's quote: "This mostly happens when someone hooks up a hose to their black tank flush and forgets they did so or gets distracted."
Though this next part should really be in a different thread, it's partially related.
"To take this conversation to another level, what do you place in your black and/or gray tanks to help keep it broke down so that you empty your entire tank completely?
You read stuff on line and half is advertising a product, but what really works. I would say no chemicals from what I have read but what about products like Tech Tanks Rx or other types of organisms that break down the solids.
Give me the short version of the TP education. We are going to the Spring Rally in 2017, but unexpectedly are starting FT next week. That is what happens when you sell everything way before you thought and purchase an RV sooner than expected."
As full-timers, we use nothing in our tanks as far as products go. You'll want to use plenty of water in your black tank, but always keep the black tank closed until it is nearly full. Never leave the black tank open while hooked up to a sewer connection - liquids drain out and solids build up and harden. As long as you are using plenty of water, the solids will break down naturally. If you still want to use a product, we recommend either "Happy Camper" or "Digest-It".
As for toilet paper, use something that is septic safe and passes the "swish" test. Take a few squares, put them in a container of water and swish them around. If they dissolve completely, you are good to go. If you are seeing toilet paper in your pipes when dumping, it's not the right kind - it should always dissolve. Not a bad idea to put a few gallons of water in the black tank after dumping to "charge" it and let it swish around in the tank while moving.
That's the short version. You'll learn more at the Rally. :)
The answer is water, water, everywhere. All you need is water. You provide the necessary bacteria to get things going (yes, the puns keep on coming) and biochemistry takes over. Plus, these are holding tanks, not septic tanks. As long as you use enough water, everything liquefies, and fluid mechanics takes over when you pull the dump handle. BTW - pouring some vinegar into the bowl and letting is sit until the next use, will help reduce calcium buildup on the ball seal. And a little baking soda is always good in any drain/holding tank to help buffer the water and reduce scale.
Barb
It seems to last through several full tanks. I'm guessing the bugs are able to hold on to the side of the tank while the "stuff" is draining out....tee heee or should I say Tee Peee
Howard - See you in a few months, thank you for the feedback :)
Ask us how we know? We had the tanks professionally cleaned and it took twice as long as usual and they showed up the pile of calcified crystals they removed during the process. Since then we can extend our boondocking time without the need to empty the tanks as frequently. No more Happy Camper for us.
Not really. You would have the same results with just using plenty of water, the 'bugs' are bacteria from your gut, that is all that is required. You do not have a septic tank, but a holding tank. You don't need to digest the wastes, merely liquefy so that everything will move smoothly when you pull the dump handle. And yes, I really am a scientist.
Jo and I have been full-time living in our fifth wheel now for almost 6 years. We never add any chemicals.
As for toilet paper, we used to use Angel Soft, but I've since changed to Scotts "septic safe" TP. Back when I used Angel Soft, I could see bits of paper floating by in the clear plastic sewer extension, even after multiple "cycles." (To me, a "cycle" is after flushing the tank for several minutes, I would close the black tank valve for 2 1/2 minutes and then re-open for 2 1/2 minutes.) After changing over to Scotts, I never see the bits of paper floating by, even after only one cycle.
Terry