Pre-fill black water tanks?

[tizzyfit]

I think part of this discussion fails to take into account the size of the different black tanks we all have. Case in point, mine is 45 gallons, so for me, traveling by myself, to add 10 gallons of fresh water after dumping creates no capacity issues. For those with a 10 or 15-gallon black tank and a family of 4 or 5, you need every ounce of capacity available to get through a 3 day weekend.

[egwilly]

Originally Posted by Gordon Dewald

Poop pyramids are a result of leaving the black valve open on a drop toilet.

If you have a macerator toilet there is nothing but slurry in the tank. Still would not leave the black valve open.

If you have a tank flusher there is not much need to prefill the tank. Keep flushing until the water runs clear. Still do not leave the black valve open between dumps.

Chemicals are practical if you are the guy selling them and making money. When hooked up the tank is dumped and flushed quite often so the amount of time the chemical is in the tank does not give it much time to work. It does give you a good feeling about keeping the tank fresh I guess, but is more psychological than realistic.

We always try to start a trip with the fresh tank full and the gray and black tanks empty.

[egwilly]

Nothing worse than waiting in line at the dump station for someone that does dump, rinse, repeat ad nauseum 6-7 times. Meanwhile, there are several of us in line waiting for Mr. Clean. Then they bring out the flush wand! Dump, flush, repeat 5 times......seriously.
Or, the guy that threw his hose down near the pit opening and let er rip! Let the next guy clean it up.....

Dump, flush and go!

[Forkyfork]

What I really miss is living in Salt Lake City and the gas stations having dump stations that were free. There was one near me that no one ever used.

Where we live now the closest dump is 35 miles away at camper world and their dump station is nasty. Ive been looking at the macerators to pump to our septic. Im not sure its such a good idea to empty them that way very often.

If there is a line we dump and leave and even hang the rinse hose up if we use it.

[Mudfrog]

Originally Posted by Gary RVRoamer

Love these black tank discussions - always entertaining!


My opinion is that many owners get far to zealous about solutions to problems that are imagined as much as real. Practices that are merely ideals get enshrined as necessary procedures. A little Common Sense goes a long way on this topic, but often seems to be missing entirely.



Yes, it's better to have some water in the tank to make sure the paper and solids dissolve. That's if you can spare the tank capacity before the next dump opportunity. If you only have a 20 gallon tank, or aren't sure when your next opportunity may be, maybe it's not worth it.


Yes, it's best to dump when when the tank is half or more full. Gives a nice Whoosh! to suck the crud out. You can always add water at dump time if you have it available (just flush the toilet several times), but it's hardly a life-or-death thing.



Nor is it necessary to dump and rinse repeatedly. Sure, go head and do it if you have time, plenty of water, and a dump handy, but no need to lose sleep if it's not convenient.

I agree, do what makes you comfy. But please, don't go through all those extra wasteful steps when people are waiting in line behind you at the dump station.

[Mudfrog]

Originally Posted by tizzyfit

I think part of this discussion fails to take into account the size of the different black tanks we all have. Case in point, mine is 45 gallons, so for me, traveling by myself, to add 10 gallons of fresh water after dumping creates no capacity issues. For those with a 10 or 15-gallon black tank and a family of 4 or 5, you need every ounce of capacity available to get through a 3 day weekend.

But the question remains,,, whether it's 20 or a 100 gallon tank, what's the advantage of adding the 10 gallons in the first place?

[smsawle]

The dish water idea is great. Makes good sense.

[beamisl]

Mudfrog,

To answer your question, here is my opinion.

When you urinate, there is so much liquid but add toilet paper and you absorb some of it. When you have a bowel movement, the mass is larger and more solid and then you add toilet paper which can soak up the urine that is left. You do urinate more often over the day, but the urine can be evaporated if you are in a very dry area.

Therefore you have more content of a solid nature rather than the liquid nature. Dry it out with dry air and evaporation and things can start to dry out. The tower of poop! This usually happens when someone goes home and does not dump and leave it for a few months and it has time to evaporate.

Adding 10 gallons of water keeps thing more moist. I only add 6 gallons of water to my black tank unless it is very, very dry where we are at.

If at a CG and we are hooked up, we keep the black and great tanks closed until we need to dump. The reason is because when the tank is full and you dump, suction pulls a lot of stuff out. If you leave them open, there is not enough liquid to keep the poop moving and it starts drying out and Tower of Poop.

When the grey fills up, I drain it. When the black gets full, I drain in. I will always top the black off before emptying it to get that suction. Don't want anything left in there. I rinse the black tank each use.

When we bought our rig used, the sensors would not work accurately. With using plenty of water and another trick, we now have them working. The other trick is this. Gallon of water, 1/2 cup of Dawn dish soap, and 1 cup of Calgon. Calgon cuts down on suds from the Dawn.

When we put this in and then drive out again, the trick splashes around cleaning the tank somewhat. It has worked but I plan to try some Happy Camper this turn around.

We do not have odors from our tanks. Hope this explains why you add water. It's your tank and you can do what works for you. We all have tricks that work for us.

Lynne

[nothermark]

Originally Posted by Mudfrog

But the question remains,,, whether it's 20 or a 100 gallon tank, what's the advantage of adding the 10 gallons in the first place?

The number of gallons is not magic as it depends on your tank size and shape.

The basic idea is to keep the load wet enough so it does not have to be hydrated again to be dumped. A lot of dry material does not instantly absorb large amounts of water so it flows. If it is already wet it does liquefy much more easily. It needs to be liquid to dump. The more liquid the better.

Possibly not an issue for the folks who move from sewer to sewer and move a lot of water through the system. A real problem for those of us who don't use our tanks continuously and don't always fill them. Most of us also do not have any kind of tank sprayer. It goes down the toilet and hand basin or it does not get there. Perhaps if the folks commenting figured out the original question some of them would rethink their answers.

[Mudfrog]

I know that my tank needs plenty of water to function adequately. My question is why prefill with any amount of water? Water gets added every time i use and flush the pot. Guess I've been doing this long enough that it's easy for me to estimate how long to hold the pedal down during each flush. Shorter stays get longer flushes and longer stays get shorter so as not to fill up the tank too quickly. There is always plenty of liquid at the end of our stay for dumping.

I've been doing this rv thing for over 40 years and in this time, have never had any tank, slide valve, or other plumbing issues. I dump at the end of our stay and no water gets added until the next time we set up camp and do some business.

[ThePowells]

Prefill the black water tank....

Isn't that done by the delivery driver on the way with your RV?

[530ktm]

Originally Posted by ThePowells

Prefill the black water tank....

Isn't that done by the delivery driver on the way with your RV?

[WhitSel]

I was recently told that dish washer “pod” do a great job of cleaning tanks and sensors, plus they are non-sudsing.

Comments? Experience?

Thanks

[Gordon Dewald]

Originally Posted by Mudfrog

But the question remains,,, whether it's 20 or a 100 gallon tank, what's the advantage of adding the 10 gallons in the first place?

Agree.

I think there may be the thought that you have water on the bottom of the tank to prevent solids from sticking or clumping.

When we had the drop toilet we always added water to the bowl prior to doing the business, more for #2 than #1. There was always sufficient water dropped with the deposit that there should have been no drying out or clumping issues.

In our 5er the washroom sink drained into the black tank. Kitchen and shower drained to gray.

In the current coach the 1/2 bath sink drains into the black tank. That along with the macerator means there is lots of water in the black.