Holding tank sizes

Gary the Wombat · 10-25-2006, 08:54 AM

It seems that I empty my gray tank about 3 times more often than my black tank. In my MH only the toilet empties into the black (the bathroom lav empties into the gray, though I believe on some, it empties into the black).

Why then, do manufactures make the 2 tanks almost the same size? Wouldn't it make more sense to put in a smaller black tank, so the gray could be made larger without taking up more room? Or is there some reason for the size they are?

Gary the Wombat · 10-25-2006, 08:54 AM

It seems that I empty my gray tank about 3 times more often than my black tank. In my MH only the toilet empties into the black (the bathroom lav empties into the gray, though I believe on some, it empties into the black).

Why then, do manufactures make the 2 tanks almost the same size? Wouldn't it make more sense to put in a smaller black tank, so the gray could be made larger without taking up more room? Or is there some reason for the size they are?

Joe-K · 10-25-2006, 11:04 AM

Gary,

Thats a great question, and a good suggestion.

Unfortunately, there's there's very few manufacturers who do that.

Hopefully they're reading this

TXiceman · 10-25-2006, 04:55 PM

RVs have been bult this way for years and the manufacturers still have not figured out people generate a lot more grey water than black water.

Ken

CD · 10-25-2006, 05:06 PM

Our Nash has 2 grey tanks, a 20 Gal & a 40 Gal. but still not enough to match the 40 Gal. black.

**Hitchhiker** · 10-25-2006, 05:17 PM

My HitchHiker (built by Nu-Wa) has a 70 gallon fresh water, 50 gallon black water, and a 70 gallon grey water tank. We've never had the black tank anywhere near full and can go about a week on the grey tank if we use it frugally. When we anticipate a need for extra grey capacity, DW will catch the dish washing water in a plastic tub and pour it into the toilet, thus the black tank.

The 70 gallon fresh water tank capacity specification includes the 10 gallons contained in the water heater.

Bob (WA0MQE) · 10-26-2006, 02:00 AM

My Fleetwood Pace Arrow has a 55-gal grey tank and a 42-gal black tank.

I don't know about 5th Wheels, but while checking motorhomes over the years to decide which ones I might be interested many of them listed larger grey tanks then black tanks. Some didn't as you mention but most did.

Joe-K · 10-26-2006, 04:24 AM

Our Winnebago has 100 gallons of freshwater, with 52 grey and 48 black. Technically, the grey is larger than the black, but I'd like to see a 70+ gallon grey and 30 black would be plenty.

GStream40 · 10-26-2006, 05:20 AM

On our Gulf Stream we have a 100 gal. freshwater, 75 gal. grey, and 75 gal. black.

We have never had a problem filling the grey tank before we ran out of water. But our bathroom sink drains into the black tank. I believe this helps.

The longest we rally we were on with no hook-ups except electricity was 5 days. At the end of the rally we were nearly out of freshwater and the grey tank was near full but not quite.

Ron

Bob&Pat · 10-26-2006, 05:37 AM

36m Sunrise / Brave has:
67 gal. Gray
40 gal. Black
76 gal. Fresh (plus 6 gallons in hot water heater)

28 gal. LP (80% = 22.4 gal. Net)
75 gal. Gas

rogueii · 10-26-2006, 07:49 AM

My Seabreese XL is 34',11" in length.
I have 75 Gallons Fresh Water, 50 Gallons Grey, and 50 Gallons Black.

Don in E Texas · 10-26-2006, 09:09 AM

Bus Conversion:

100 Black
100 Grey
100 Fresh (plus 20 gallons in hot water heater)

Reason? They all fit in the same area space-wise and the cost about the same. As others have said, can dump dish water into black tank if needed.

Airstream:

Far too small (but then it is a small, light, TT. Tanks fit the RV size). We have used the black tank to hold dish water and that is a big help.

don

Gary the Wombat · 10-26-2006, 10:09 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Don in E Texas:
Bus Conversion:

100 Black
100 Grey
100 Fresh (plus 20 gallons in hot water heater)

Reason? They all fit in the same area space-wise and the cost about the same. As others have said, can dump dish water into black tank if needed.

Airstream:

Far too small (but then it is a small, light, TT. Tanks fit the RV size). We have used the black tank to hold dish water and that is a big help.

don </div></BLOCKQUOTE>

My point exactly--if manufacturers realized that the majority of us use far more gray water than black, they would install appropriate ratios of tank sizes so we didn't have to do things like collect dish water in buckets to dump down the toilet. I don't know about the rest of you, but I rarely boondock, so the size of the freshwater tank is not very important to me. It just seems to make sense to me that the gray water tank should be about 2 to 3 times the capacity of the black water.