New Questions / New Ideas / Mod? Just Thinking Out Loud

[4x4van]

Hot water for the toilet might be nice, but depending on how far the toilet is from the water heater, it will take a significant amount of water - wasted - before the hot actually shows up at the loo.

BTW, my bathroom sink is indeed plumbed to the black tank, not the grey. Winnebago does that on some models, simply due to the layout and where the tanks are located.

The easiest way to do what you want is to get a twist on sewer valve, and simply open both your black and grey valves to allow gravity to equalize your tanks:

https://www.amazon.com/Valterra-T58-...31038926&psc=1

[dkoldman]

Originally Posted by 4x4van

Hot water for the toilet might be nice, but depending on how far the toilet is from the water heater, it will take a significant amount of water - wasted - before the hot actually shows up at the loo.

Hot water supply is about a foot away. Plus the point is the water in hot water heater tank is already hot just sitting there. Most of time it just sits and goes cold due to low usage. Yes this is 100% just a nice to have. We can use the Shower's Shower head to direct hot water in the tank now.

BTW, my bathroom sink is indeed plumbed to the black tank, not the grey. Winnebago does that on some models, simply due to the layout and where the tanks are located.

The easiest way to do what you want is to get a twist on sewer valve, and simply open both your black and grey valves to allow gravity to equalize your tanks:

https://www.amazon.com/Valterra-T58-...31038926&psc=1

If I follow, I can do that now. When I finish draining my Black tank today, I leave the black tank valve open, but I close the output valve. I then open the gray tank and let it backfill into Black tank for a few minutes. I stop close off Gray and reopen the black and drain again. I do this a few times and then sani flush the black tank.

I likely will not do a diverter valve inside because I can pump with my Flo Jet macerator with a push of button and the connection of hose to Sani Flush port.

[BobC]

Originally Posted by dkoldman

If I follow, I can do that now. When I finish draining my Black tank today, I leave the black tank valve open, but I close the output valve. I then open the gray tank and let it backfill into Black tank for a few minutes. I stop close off Gray and reopen the black and drain again. I do this a few times and then sani flush the black tank.

I likely will not do a diverter valve inside because I can pump with my Flo Jet macerator with a push of button and the connection of hose to Sani Flush port.

I don't know if this is an issue, maybe it's just me, but won't this contaminate your gray tank? In any case, is equalizing water levels going to be adequate?

I like your macerator idea. In terms of clogging your black water tank's clean-out nozzle, you could use an inline filter designed for drip irrigation systems. They're relatively inexpensive and are easily cleaned out. You'll want to be careful and not get too fine a mesh. As long as it's not bigger than your cleanout input's screen you should be OK. The inline filter won't clog as quickly due to its size.

https://www.google.com/search?q=inli...ih=632&dpr=2.2

[dkoldman]

Originally Posted by BobC

I don't know if this is an issue, maybe it's just me, but won't this contaminate your gray tank? In any case, is equalizing water levels going to be adequate?

To be clear, I never said I equalize water levels. That was a suggestion made by 4X4van; but it reminded me that I have that capability. However the process I described does NOT equalize. I have an emptied black tank that allows a hard rush of gray water to back fill. Due to the weight of water and pressure if you follow it will always have directional force to the black tank. I may leave it open for like 15-20 secs each time. I may do this 2 or 3 times before I completely drain the gray tank. It is pretty effective for cleaning my black tan BEFORE I use my Sani Flush, plus I get maximum use of water.

I like your macerator idea. In terms of clogging your black water tank's clean-out nozzle, you could use an inline filter designed for drip irrigation systems. They're relatively inexpensive and are easily cleaned out. You'll want to be careful and not get too fine a mesh. As long as it's not bigger than your cleanout input's screen you should be OK. The inline filter won't clog as quickly due to its size.

https://www.google.com/search?q=inli...ih=632&dpr=2.2

You may have missed, but the input to my Sani Flush for black tank already has a inline filter and it is pretty small. We don't have any solids from Gray tank anyway. I have not hooked it up to pump yet; but when I do I may get fancy with making a special 2 ft hose specifically for this purpose and a 2nd inline filter is good suggestion for consideration. It is amazing how all of these ideas has resulted in solutions that is not something that I had considered originally.

For now my next steps are to calculate how long it takes my FloJet Macerator to pump 15 gallons of gray through 5/8" garden hose? Let's assume it takes 60 seconds. Then in future if I ever need to do this, I will only add 15 gallons (60 secs) of gray to my black tank. That will effectively take my capacity from 61 gal Gray / 40 gal Black to 76 gal gray to 25 gal black. That will suit us nicely and reduce by 40% the dumps on the black tank. Not the mention the added benefit of get more water in my black tank.

With all of this said, if I find a professional that will install a diverter valve to black or gray that I can access it from under Bath sink; along with swapping the hot water supply to the toilet, I will have this done as long as price is reasonable. I saved $7k by not buying the crazy price extended warranty; so I try to spend $1,500 / year on stuff that I want to do things that I view as cool. I got 1 1/2 year left on what would have been a 5 year warranty. I think I have about $ 3,000 left as I have yet to pay for anything that would have been covered by an extended warranty (knock on wood)

[bigb]

Originally Posted by dkoldman

For now my next steps are to calculate how long it takes my FloJet Macerator to pump 15 gallons of gray through 5/8" garden hose? Let's assume it takes 60 seconds. Then in future if I ever need to do this, I will only add 15 gallons (60 secs) of gray to my black tank.

I'm going to guess it will take longer, I timed my outdoor spigot for estimating my fresh water fill and I get 1 gallon every 12 seconds, or 5 gallons/minute. That's with the faucet wide open and no pressure regulator. I think my white hose is only 1/2" though. It will be interesting to see the GPM on a macerator thru a 5/8" hose though.

[dkoldman]

Originally Posted by bigb

I'm going to guess it will take longer, I timed my outdoor spigot for estimating my fresh water fill and I get 1 gallon every 12 seconds, or 5 gallons/minute. That's with the faucet wide open and no pressure regulator. I think my white hose is only 1/2" though. It will be interesting to see the GPM on a macerator thru a 5/8" hose though.

Ok, so you made me check. I love my FloJet Macerator. Why do you think I sweat it dumping at Campsites I don't want to get in line at dump stations, and I don't want anybody behind me when I am trying to take my time to get it clean. I don't like being hard plumbed at a campsite short electrical hookup, I did a mod there that make that a snap and less than 30 secs.

Anyway, the RV FlowJet Macerator can do 13 Gallons/min on 5/8 garden hose, or dump a 30 gallon waste tank in less than 3 minutes.

https://www.campingworld.com/flojet-...E&gclsrc=aw.ds

RV Macerator Pump

Designed to add flexibility to Holding Tank service. With the Flojet Waste Pump, you can not only empty the black and grey water tanks at the conventional Dump Station but also down a toilet, into your house sewer clean-out, septic tank, or into a mobile waste wagon.

The Flojet macerator pump will empty a typical 30-gallon holding tank in less than three minutes. The time increases somewhat as the distance pumped is increased beyond 25'. The pump will macerate and pump all waste and tissue normally found in RV waste systems. The same high-quality Jabsco design is found in boat stores worldwide. Put an end to handling and rinsing a dirty 3" sewer hose; instead use a cleaner, easier to handle garden hose. Now you can pump uphill, and around corners. The RV waste pump will simplify and improve your RV experience!

Features:

A neat and clean way to quickly evacuate waste tanks
Empty black-water and greywater Holding Tanks at home
Grinds waste as it pumps
Built-in Impeller Protection Device...longer life!
The flow of up to 13 GPM for fast, clean Holding Tank evacuation

So you can see why I love doing this at home. The more I can maximize my current waste tank holding the capacity (61g Gray / 40g Black) the less need I will have for dumps on the road.

[dkoldman]

I went ahead and rig this up. This is what it looks like. I just open the gray valve, turn on pump, gives it 60 seconds and I am done. I have 38% mix of gray water in my black tank with total capacity of 40 gallons. In the meantime, I would have remove 15 gallons of gray from my 61 gallon capacity gray tank.

[dkoldman]

I was looking at a brand new 2022 Adventurer 35F and was floored with the $204,000 price and then I saw....

Fresh Water Capacity 84 gals
Grey Water Capacity 51 gals
Black Water Capacity 62 gals

and I thinking how our 61 gal Gray water is not enough for us? Maybe that coach has bath sink(s) going to black water?

[dkoldman]

Originally Posted by dkoldman

I went ahead and rig this up. This is what it looks like. I just open the gray valve, turn on pump, gives it 60 seconds and I am done. I have 38% mix of gray water in my black tank with total capacity of 40 gallons. In the meantime, I would have remove 15 gallons of gray from my 61 gallon capacity gray tank.

So I decided to give this a try this morning to see what actually happens. Some of the data is to keep me align for future but would love to hear thought and suggestions.

This is how the test started

Gray tank = 61 gal capacity reading 1/3rd tank
Black tank = 40 gal capacity reading 1/3rd tank

I added an additional filter inside my 5 ft hose. See picture. So there are two inline filters. (Sani Flush & 5 ft Hose I made)

Pass 1
I pump for 60 secs and close gray valve. Pump runs for another 30 secs to clear between closed valve and what was inline.

Gray tank reads 1/3 tank
Black Tank reads 1/3 tank

Pass 2
I pump for 60 secs and close gray valve. Pump runs for another 74 secs to clear between closed valve and what was inline.

Gray tank reads 1/3 tank
Black Tank reads 2/3 tank

Pass 3
I pump for 60 secs and close gray valve. Pump runs for another 120 secs to clear between closed valve and what was inline.

Gray tank reads E tank
Black Tank reads 2/3 tank

Observations

- Black tank started with at least 13 gal and has at most 25 gal.
- The most I could have pumped was 26 gal as Black never went Full (39g - 13g)= 26g
- The least I could have pumped is 1 gal if Black went from 1/3 (25g) to 2/3 26g
- 3 min of pump time aided by pressure
- 3 min 44 secs of pump time with valve close

Questions

- could there be a point within the black tank where input is under pressure from within the tank to allow the pump to work as efficiently?
- could the 2nd inline filter be reducing too much pressure? Note: When finished, there was no debris in any of the inline filters.

Takeaway for next time
- I will only attempt this procedure if Black tank has reading of 1/3 tank or less
- Start with 2 min pump time and if more is required drop to 1 min pump time.
- Reduce the 5 ft hose to 2 or 3 ft to remove the drop and curve to make it easier on pump and less gray in the hose.

I hope to get chance to drive the RV to help mix and blend. I will dump both tanks in full soon before next trip which is less than two weeks away. It will be that trip that I may have the need to add 15 gal gray to black tank.

[dkoldman]

Originally Posted by dkoldman

So I decided to give this a try this morning to see what actually happens. Some of the data is to keep me align for future but would love to hear thought and suggestions.

This is how the test started

Gray tank = 61 gal capacity reading 1/3rd tank
Black tank = 40 gal capacity reading 1/3rd tank

I added an additional filter inside my 5 ft hose. See picture. So there are two inline filters. (Sani Flush & 5 ft Hose I made)

Pass 1
I pump for 60 secs and close gray valve. Pump runs for another 30 secs to clear between closed valve and what was inline.

Gray tank reads 1/3 tank
Black Tank reads 1/3 tank

Pass 2
I pump for 60 secs and close gray valve. Pump runs for another 74 secs to clear between closed valve and what was inline.

Gray tank reads 1/3 tank
Black Tank reads 2/3 tank

Pass 3
I pump for 60 secs and close gray valve. Pump runs for another 120 secs to clear between closed valve and what was inline.

Gray tank reads E tank
Black Tank reads 2/3 tank

Observations

- Black tank started with at least 13 gal and has at most 25 gal.
- The most I could have pumped was 26 gal as Black never went Full (39g - 13g)= 26g
- The least I could have pumped is 1 gal if Black went from 1/3 (25g) to 2/3 26g
- 3 min of pump time aided by pressure
- 3 min 44 secs of pump time with valve close

Questions

- could there be a point within the black tank where input is under pressure from within the tank to allow the pump to work as efficiently?
- could the 2nd inline filter be reducing too much pressure? Note: When finished, there was no debris in any of the inline filters.

Takeaway for next time
- I will only attempt this procedure if Black tank has reading of 1/3 tank or less
- Start with 2 min pump time and if more is required drop to 1 min pump time.
- Reduce the 5 ft hose to 2 or 3 ft to remove the drop and curve to make it easier on pump and less gray in the hose.

I hope to get chance to drive the RV to help mix and blend. I will dump both tanks in full soon before next trip which is less than two weeks away. It will be that trip that I may have the need to add 15 gal gray to black tank.

This did not work on my 2nd attempt of actual usage. On a trip this week when I tried to pump 15 gallons from gray to black it clogged the filter I had inserted in my hose. It also clogged the input filter for sani flush. It was not a solid material but more like a paste? I am thinking it may from Seafood restaurant in Houston where we ordered but able crawfish in the RV? If true that may be an exception because last time it worked flawlessly.

As a precaution, I went ahead and dumped both times and cleaned them out again. My Gray was at 2/3 full and Black was at E Full. I was hoping to make both 1/3 Full. I fill like I am wasting my chemical treatments dumping too soon. Yes I could just dump the gray only, but if I connect everything up to pump, I am gonna dump it all.