RV holding tank capacity

10-19-2011, 11:56 AM

After 7 years of TM ownership I've gotten pretty accurate at judging the capacity of the Thetford. (About 8-9 "user days" or a 4 day weekend for DW and I before we need to pull the valve and use the super secret emergency reserve.)

My question is, how does this correspond to using a standard RV flush toilet and black water holding tank? Put otherwise, how many user days are there per 10 gallons of black water holding tank capacity? Thanks! -camp2canoe

**ShrimpBurrito** · 10-19-2011, 02:14 PM

According to my calculations, if the flushing toilet consumes 1.5 pints of water per flush, you'll need a black water tank of about 10 gallons to get about the same user-days as what you get out of the Thetford.

See this thread:
http://www.trailmanorowners.com/foru...ad.php?t=10956

Dave

10-19-2011, 07:50 PM

In other words just about any black water tank out there will give you more capacity!

**ShrimpBurrito** · 10-19-2011, 08:07 PM

Maybe. But regardless, even with equal capacity, it comes with added weight and decreased fresh water supply. Those are big drawbacks.

Dave

10-21-2011, 06:39 AM

So we just roll out the reserve..... nothing is perfect. All give and take....

10-21-2011, 08:05 AM

Thanks to all! - camp2canoe

10-22-2011, 03:35 PM

Here's our experience with the Elkmont's black water tank:
http://www.trailmanorowners.com/foru...ad.php?t=11902

Although we haven't tested the new tank yet for a full 7 days, I think 30gals should be enough for a week. We'll see when we're in Florida (leaving in just a few days!).