Black tank deposits.

[deank1]

We are having a problem with what appears to be a coating/deposit flaking off the inside of the blank tank. We used Thetford dry additive for a couple of yrs and had odor problems, someone suggested we add dishwasher detergent to clean the tank. Not sure if that had anything to do with the problem but the scale comes off in large pieces at times. I was using a Sewer Solution unit but the pieces plug it up so now I am back to using the big blue hose. Anyone out there have a problem with hard scale in the black tank?

 

[Steve CDN]

It sounds like your powder additive caked in the tank and perhaps your tank was stored empty of any water during periods of inactivity.

I would suggest connecting a hose to a hot water house faucet and feeding a hot pressure stream of hot water into your black tank through the toilet.

Drive around with the hot water for a while so there can be some agitation, then dump the tank.? You may have to repeat the process but that would be one way to dissolve the accumulation.

Many RV Forum members don't like holding tank additives, but I use a liquid additive that breaks down deposits and lubricates the valve gaskets.

If you are going to use an additive, use liquid, and always keep water in the black tank.

Of course one never leaves the black tank valve open while parked and connected to a sewer

 

[Terry A. Brewer]

>> Anyone out there have a problem with hard scale in the black tank?<<


i had mine professionally pressure washed & had those same sheets of scale that I attribute to the hard waters in the west that accumulated on the sides over time.

 

[Carl L]

>> Anyone out there have a problem with hard scale in the black tank?<<


i had mine professionally pressure washed & had those same sheets of scale that I attribute to the hard waters in the west that accumulated on the sides over time.

Could it possibly be dried TP?  The kind that is not safe for septic tank use.  Like Thetford?

 

[Terry A. Brewer]

Carl

>>Could it possibly be dried TP?? The kind that is not safe for septic tank use.? Like Thetford?<<

No I only used Scott's single ply. These were about the consistency of thin ice & about as brittle, they came off as he pressure washed the sides of the tank.

 

[Gary RV_Wizard]

Scale is pretty normal on a black tank - it's a coating of crud that dries on whenever the tank is empty. It happens more to occasional Rvers than to fulltimers, since he fulltimer's tank is rarely empty & dry.

 

[wesh]

I want to thank RV Forum and each who contributed to this topic.  I am new to this forum and appreciate what all of you are doing.

We have an ongoing problem of a terrible odor from our black tank that doesn't smell like feces or urine. It is a distinctive SOUR, foul smell that drives us out of our coach.  I wash it and wash it and wash it; then, after a day or two, the odor returns.

I got some good ideas from each of you and admire what you are doing so unselfishly.

Wes Hackbarth
Las Vegas, NV 

AKA wesh

[email protected]

 

[Carl L]

Carl

>>Could it possibly be dried TP?? The kind that is not safe for septic tank use.? Like Thetford?<<

No I only used Scott's single ply. These were about the consistency of thin ice & about as brittle, they came off as he pressure washed the sides of the tank.

You know it might be potassium/sodium nitrate.  That was a common deposit in old fashioned cesspools and back in the old days it was used as a source of KNO3 for gunpowder.

 

[Carl L]

We have an ongoing problem of a terrible odor from our black tank that doesn't smell like feces or urine. It is a distinctive SOUR, foul smell that drives us out of our coach.? I wash it and wash it and wash it; then, after a day or two, the odor returns.

[email protected]

Is the smell the rotten egg smell of hydrogen sulfide?

 

[Gary RV_Wizard]

Deank1,
Are you sure it's the black tank?  There is a microbe that sometimes thrives in water heaters of RVs that has a sour, sulphur odor and is sometimes mistaken for tank odor.  It is often most noticeable after running warm water in the sink. Has also been known to live in sink drains.  And of course gray tanks can easily get that odor from food wastes.  If your sink traps don't keep water in them, the graytank odor canback up into the room.

Assuming it is the black tank, do you get odor only when you flush or does it build up in the room even when the toilet is not used?    If the latter, what brand and model toilet is it?

Also, what have you tried to clean it out with so far?

 

[wesh]

Being new to the Forum, I can't figure out how to reply the nice folks who are trying to help me.  I went to the help portion but it seems inadequate.  No,  I seem inadequate.  That's more accurate.


Wes Hackbarth AKA wesh

[email protected]

 

[Ned]

Wes,

For a public reply, do just what you did.  If you want to contact a staff (or any) member privately, you can use the IM icon under the member name.  If an envelope icon is there, you can use that to send an email.

 

[Karl]

Wes,

The odor could be because of a blocked vent tube on the roof. Tie a heavy bolt or something else to some fishing line and drop it thru the opening to check if that's the problem. Wasps and spiders will sometimes build nests inside openings like these.

 

[Rex]

Well, I have had the same thing, and I also use the Sewer Solution.  I found that by using the Sewer Solution jet valve and turning it, I could clear the blockage.  I would close the black tank valve, clear the Sewer Solution, disconnect it and let the flakes fall out.  Then go back to normal dumping.  I would get the flacks about every 10 dumps. 

You might try filling the tank about 1/4 full, then put 1 - 2 bags of crushed ice down the toilet.  Then drive around about 30-minutes, and make lots of turns.  The ice will do a job on flake removal.  You will still get some flakes from time to time, but you can repeat this ice process and take care of it.  After you finish the 30-minute drive, you can dump using the slinky hose.  If you want to use the Sewer Solution instead, wait about 2-hours more so that all the ice has time to melt.

I hate the slinky hose, and have used only the Sewer Solution for 6-years.

Rex

 

[Karl]

You know it might be potassium/sodium nitrate.  That was a common deposit in old fashioned cesspools and back in the old days it was used as a source of KNO3 for gunpowder.

Gee Carl, if that's the problem he could just throw a handful or two of sulfur and charcoal down the toilet, and let it dry out. One match and POOF!  No more flakes ;D ;D ;D (also, no more MH)