# "stuff" Growing In Black Water



## Boomer2012 (Aug 31, 2011)

Hopefully all of your breakfast has been digested prior to reading. We bought our new 2012 250rs in March and love it. We have camped twice in April and May and just get the trailer out this weekend for our next trip. Prior to the trip in May, I thoroughly flushed the black tank -- here is my routine. Dumped at the departure campground. Filled a few gallons of water and added a dishwasher disolvable detergent packet to slosh around while driving home. Dumped again at home. Thorough clean with spinning wand thingy until water flows nice and clear.

Here's where the debate will likely begin as I have seen varying forms of advice on how to store the black water tank (empty, full, other?). In previous instances I stored it empty with the outside valve closed. After reading a lot on the subject I decided to try a cap with holes in it for added ventilation while in storage. So this time (I am beginning to regret this decision) I put on a vented cap (holes about hte size a 2" nail would make) and left the black valve open (left a bucket under it to catch any residual).

Here's what I found on Sunday: there was DRIED brown "stuff" that was weeping out of the holes of the cap, and also stuck inside near the end of the drain. I even saw something green growing like a sprout. When I opened the toilet and looked down with a flashlight (I can see straight to the bottom of our tank) the bottom was covered with the same dried brown stuff in a thin layer. It did not smell. I saw two flies on the inside of the outside cap but nowhere else. I wanded again and the black tank is now visually clean.

I have since added about 2 gallons of water and some over the counter RV black tank chemical treatment. This is a first for me, so...

Questions:

1. I assume the perforated vent cap plus the open valve is a strategy that should be abandoned immediately, correct? Should I close the valve and apply the normal cap on the outside?

2. What do you do with the black tank when you are storing it short and long-term (a little water and some treatment? water only? dry? and does it differ depending on usuable months vs. winterized?)

As always, thanks for the advice.


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## Oregon_Camper (Sep 13, 2004)

I don't want to be in the RV storage site next your trailer....whew!!!









Joking aside, I would never go with the tank valve open. The tanks are manufactured to be closed when not being emptied. I have always emptied tank...flushed with Quickie Flush until clear water flows...then close valve for a few minutes, allowing 4-5 gallons of water to stay in the tank. Then drop in a chemical packet and call it done. I have never had any issues...so why change.

In the winter I will remove all water and dump a full 5 gallon jug of antifreeze into the black tank with no chemicals.


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## Boomer2012 (Aug 31, 2011)

Oregon_Camper said:


> I don't want to be in the RV storage site next your trailer....whew!!!
> 
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> ...


No kidding -- its nothing compared to camping next to me! Good advice and a strategy I am adopting immediately -- for our sake and all around us.


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## Bill & Kate (Apr 28, 2012)

Oregon_Camper said:


> I don't want to be in the RV storage site next your trailer....whew!!!
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> 
> 
> ...


X2, except I don't worry about dumping extra antifreeze - whatever ends up in the tank once the toilet is run long enough to get the pink stuff all the way through the system. I figure even if a gallon or two of weak antifreeze solution freezes up, it won't get that hard because of the antifreeze, and since there is so much space in the tank compared to the volume of ice, expansion should not be a problem. Do the same with the gray tanks ....


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## duggy (Mar 17, 2010)

X3

I dump the tank after camping, flush to varying degrees, depending on facilities available, and if there is a lineup waiting for me to finish. Then I add a few gallons of water, and some toilet chemical. Each evening that we're camping, we add a little more chemical before going to bed. We've never had a stinky toilet.

When it's time to winterize, I thoroughly flush the tank until there is nothing but clear water running. Then I take a drive down a back road, with the valve open, and slosh any remaining water out. (I live in a rural area. That last suggestion might get some people in trouble.) Whatever plumbing antifreeze ends up in the tanks during the winterizing process, is left in them for the winter. I leave the valves closed for the winter.


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## MJV (Apr 19, 2012)

X4 The tank valves should allways be left closed except when actually dumping. The rubber seals could go out of shape, and then may not seal properly! Adding a proper holding tank chemical is also a must as well as other procedures taken by the responders to this post. M.V.


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