When we are in camping mode our trailer gets the, use plenty of water each flush - make sure black tank is full - dump (or pump with macerator) - flush - add 2 gallons - repeat as necessary routine. I typically don't find a need to add chemicals during this process.When we are not in camping mode our trailer is used as a guest house, or is parked/used at our remote farm property. In either case the black tank will be used occasionally and it will sit for months at a time. Over the last two years of doing this I add a toilet chemical to the tank and have had no problem dumping/pumping the tank after these long periods of inactivity.I have been using a toilet chemical that was in a large bottle and one that I've had under the sink in the trailer for years. Some time ago I used the last of this chemical and of course given I have CRS I can't remember what brand/type it was. And I don't even know if it was a chemical that would actually break down waste or just a smell masker. It was a thickish blue liquid.I would like to buy some more chemicals that are designed to break down the waste, not just mask the smell. I do not like the kind that is in the little plastic bags that supposedly disintegrate in the tank. The one time I tried those I found they disintegrated in the storage bag just fine. I would prefer liquid unless there is maybe some type of granular that would come in a small bucket.What are my options for a chemical that will work on breaking down the waste over time?Thanks

Actually, the best chemical to put in your black tank is WATER!Remember, it is a HOLDING tank, not a SEPTIC tank.If you do a search for home septic system maintenance, you will get more reading material than most people can cope with. In general, all articles will tell you that everything needed to break down human waste is already IN the waste, nothing needs to be added.That's right, all the septic tank enzyme treatments are a waste of money!Especially when used in an RV holding tank.The holding tank chemicals are mostly perfumes or deodorants. While they may help control odors, they do little to break down the solids. The water does that.Search Amazon for RV holding tank chemicals, or check your local RV dealer, and buy whatever looks good to you. More costly does not equate to "better".

mowermech wrote:Actually, the best chemical to put in your black tank is WATER!Remember, it is a HOLDING tank, not a SEPTIC tank.If you do a search for home septic system maintenance, you will get more reading material than most people can cope with. In general, all articles will tell you that everything needed to break down human waste is already IN the waste, nothing needs to be added.That's right, all the septic tank enzyme treatments are a waste of money!Especially when used in an RV holding tank.The holding tank chemicals are mostly perfumes or deodorants. While they may help control odors, they do little to break down the solids. The water does that.Search Amazon for RV holding tank chemicals, or check your local RV dealer, and buy whatever looks good to you. More costly does not equate to "better".+1Since I have a family of 5 and am on a septic system, I completely agree with the above. The only things ever added to my septic system are:-water-poop-pee-toilet paper-sometimes a little brewer's yeast in warm water to kick start the system after a long period of inactivity (2 week vacation)Let the poop sit in the holding tank. When ready to dump in a few months, completely fill with water and let it sit for a couple days if possible, you might add a little detergent to help get sticky walls a little bit cleaner.

Any good enzyme-based holding tank additive will break down the solid waste - I've had good luck with both the Unique RV Digest-It liquid and the Happy Camper enzyme powders. Enzyme products need stuff for those little critters to chew on, so don't know how they hold up with minimal input. I'm currently using the Happy Camper stuff and almost never see any solids going thru the pipe when I dump.al

Here's a couple thoughts, maybe not the answer you're looking for, but something to consider.We've parked at the in-laws farm for week-end visits and use the camper for our bedroom space. My father-in-law (who farms) told me to just go ahead and drain the black and gray tank (I use my blue tote) and wheel it out into the field and let it go! Any paper will disintegrate and get turned over in the next plowing or disking, the rest is pure fertilizer. So I hook the tote up to his riding lawn mower and pull it into the field behind the house and "let it fly!" If you live on your own farm, you can do the same. That way,your tanks don't have to sit full for long periods.Another thing we do all the time (in the summer, but we have our winter version too). We use the toilet when we're home, and simply drain into our blue tote and (because we live in the country), I have a spot where I can dump it on the ground, away from the house. By the way, that's the most beautiful grass in the entire property too!Most of the time, when doing the "#2" we go in the house, so it's just mostly the "#1" we're dumping.Now, in the winter, we keep a port-a-potty in the camper and we use it, because it's COLD 'out there' when snow is on the ground! So in the morning, (I) just take the bucket and dump it right down the toilet inside the house. Been doing this for 15 years now!If you really want something to start a fermentation process in your RV tanks, then any kind of emzine product will work. Rid-X to Bio-Chem for your sink drains. And actually, a rotten tomato will also jump start the fermentation process too!

Which black tank chemicals break down waste? | Good Sam Community

20 Replies

Gdetrailer
Explorer III
Nov 14, 2013
Wishbone51 wrote:
RCMAN46 wrote:
But regardless I do not recommend leaving anything in a RV holding tank for more than a week. The pyramid may become a problem if you do.

If you have plenty of water, the pyramid won't be an issue.

That depends.

On how long you let the tank "sit" and just how much actual "water content" there is vs "solids.

The danger is with letting a holding tank sit for any amount of time with "solids" in it is the fact that water in the tank EVAPORATES through the open vent on the roof.

Couple that with say hot weather in the summer while it "sits" a month or two and you will have something even worse than the dreaded "pyramid".

You typically do not have evaporation issues with home septic systems since most are non vented and buried into the earth which keeps the tank temps rather cool even in the summer heat. Any water evaporation would be extremely slow if any.

Holding tanks however are a horse of a different color since they are 1 Open to the air
2 get extremely hot in the summer which speeds up evaporation
3 Winter time presents freezing temps which if the tank is near full can present a real messy disaster when it thaws out :E

Personally it doesn't take all that much time to flush out the solids and doing so allows you to come back to a empty tank with no "surprises" to worry about.

Couple of "options" to think about if trailer is in a place with no "legal" dump site...

If you have a truck get a 55 gallon plastic drum a maceration/sewage pump. Pump the holding tank into the drum then take the drum to a legal sewage dump site and empty the drum.

Use a blue tote instead of drum but you might want to use the maceration pump so you can have the blue tote in your truck bed (lifting more than 20 gallons would be a "challenge")..

I would however not suggest just strait dumping raw sewage on the ground, doing so can and does spread unwanted diseases (think about some of the major E coli issues over the last few years which are a direct result of using human waste for fertilizers in other countries)... Not to mention may result in unwanted "guests" serving you some expensive fines...
Wishbone51
Explorer
Nov 14, 2013
RCMAN46 wrote:
But regardless I do not recommend leaving anything in a RV holding tank for more than a week. The pyramid may become a problem if you do.

If you have plenty of water, the pyramid won't be an issue.
RCMAN46
Explorer
Nov 14, 2013
Correct I did get the term wrong. When I looked up to make sure I got the correct spelling either I had a brain ^&% or Windows 8 decided it knows more than I and changed the spelling for me. I have had W8 respell words many times.

Any way I was not aware there were aerobic septic systems. You learn new things every day on this forum and sometimes find out you do not know as much as you thought.

But regardless I do not recommend leaving anything in a RV holding tank for more than a week. The pyramid may become a problem if you do.
Nvr2loud
Explorer II
Nov 14, 2013
BarneyS wrote:
RCMAN46 wrote:
A septic tank is aerobic which is required for the bacteria to break things down. Your holding tank is not aerobic as it has a vent to the atmosphere. As such it will not break down the material thus it has to be flushed every couple days. I would not let anything stay in the tank for more than a week. Water is the holding tanks best friend.

There are both anaerobic and aerobic bacteria. The aerobic ones require oxygen and the anaerobic do not. I think you have your terms backwards in the post above. I also don't think it matters to the septic/holding tanks which kind they are. The bacteria will break down waste in either one if the material stays in the tank long enough and there is moisture present. Most RV holding tanks get emptied long before any decomposition can take place though, so just water is all that is usually required.
Barney

True, but most septic tanks are anaerobic and therefore the aerobic bacteria that enters the system die off.
wrenchbender
Explorer
Nov 14, 2013
I only use baking soda to suppress the odor,cheap and plentifull. When done I just hose it out.
BarneyS
Explorer III
Nov 14, 2013
RCMAN46 wrote:
A septic tank is aerobic which is required for the bacteria to break things down. Your holding tank is not aerobic as it has a vent to the atmosphere. As such it will not break down the material thus it has to be flushed every couple days. I would not let anything stay in the tank for more than a week. Water is the holding tanks best friend.

There are both anaerobic and aerobic bacteria. The aerobic ones require oxygen and the anaerobic do not. I think you have your terms backwards in the post above. I also don't think it matters to the septic/holding tanks which kind they are. The bacteria will break down waste in either one if the material stays in the tank long enough and there is moisture present. Most RV holding tanks get emptied long before any decomposition can take place though, so just water is all that is usually required.
Barney
Nvr2loud
Explorer II
Nov 14, 2013
RCMAN46 wrote:
A septic tank is aerobic which is required for the bacteria to break things down. Your holding tank is not aerobic as it has a vent to the atmosphere. As such it will not break down the material thus it has to be flushed every couple days. I would not let anything stay in the tank for more than a week. Water is the holding tanks best friend.

Most septic tanks are anaerobic, not aerobic. The vented holding tank in an RV is aerobic. I am currently looking at changing my septic tank at home from the standard anaerobic to aerobic because it is far more efficient.
RCMAN46
Explorer
Nov 14, 2013
A septic tank is aerobic which is required for the bacteria to break things down. Your holding tank is not aerobic as it has a vent to the atmosphere. As such it will not break down the material thus it has to be flushed every couple days. I would not let anything stay in the tank for more than a week. Water is the holding tanks best friend.
BarneyS
Explorer III
Nov 14, 2013
I use this product when storing our trailer for any length of time. When camping, I just use plenty of water. Never have had any kind of holding tank problem.
Barney
mowermech
Explorer
Nov 14, 2013
Agreed! DO NOT do it anywhere in Montana, either!
It IS illegal!