How big should my skoolie gray water tank be?
We purchased the same size gray water tank as we did fresh water tank in our
Shop the water tank that we bought!
Where did you purchase your gray water tank from?
We purchased both our gray water & fresh water tanks for our
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Click here to read about the blog on “How much water does a family need living in a skoolie?“ This can be a helpful read if you aren’t sure what size gray and fresh water tanks you’ll need yet.
Go for the largest size gray water tank possible
Why? Well, a few reasons:
- There isn’t a big price difference between the next size down from 100 gallons.
- There isn’t a huge difference in dimensions between those same same referenced above, so installation wasn’t an issue.
- It’s stinky work to drain your gray water.
Living in a
A word to the wise though, don’t let your gray tank overflow – it stinks (even if you treat it!).
How long does a 100 gallon gray water tank last for a family of five?
We are a family of five (2 adults, 3 young children), and we dumped our 100 gallon gray water about once a week.
For a single person, you you could probably go two to three weeks without needing to dump your gray tank.
Where do you install your gray water tank in a skoolie ?
We mounted our gray water tank underneath our bathroom area, at the left rear of the bus. Our fresh water tank is mounted on the right rear of the bus, so they balance each other out when each is about 50% full.
How much does 100 gallons of gray water weigh?
According to World Atlas, one gallon of water weighs 8.3 pounds. Therefore, 100 gallons weighs approximately 830 pounds.
Skoolie gray water tank maintenance
How often do you need to dump your gray tank?
In our experience, as often as we filled our freshwater tank, we needed to dump our gray tank. In theory, you will not have the same water out as the amount of water in, BUT our best practice is to fill and dump at the same time or close to to avoid overflows of the gray tank (it’s stinky!).
How much time does it take to dump 100 gallons of gray water from the gray tank?
It takes about 20 minutes to dump our 100 gallon gray water tank with the valve fully open. In hindsight, we could have installed a larger valve to let water flow out faster, but honestly it wouldn’t be a huge time saver.
Where did you dump your gray water while boondocking?
The water in the gray water tank is composed of used sink & shower water, some soap, and pee! Though a little gross, it’s completely safe to dump it basically where ever you want… though use discretion! It stinks!
Since it smells, our best practice when boondocking or being off-grid is to look for large fields or perhaps grocery store parking lots with green space or a sewer drain nearby and drain there while shopping.
What happens when your gray water tank is full?
If your gray water tank is full, it’s going to come out of the first available outlet. It’s a stinky mess when that happens so create a routine to check on water levels, treat the water to reduce odor and to dump your gray water on schedule to minimize this from occurring.
Can you leave your valve open on your gray water tank so it constantly drains?
As long as you aren’t draining right below your rig, that’s completely fine technically. Gray water stinks, even if you treat it. It’s the equivalent of standing in a puddle of old pee.
Long term stay: If you can attach a drain hose to the gray water tank valve so it drains to either a sewer (like at an RV park) or field, then this is a good option for a long term stay.
Short term stay: If you are boondocking or staying somewhere without proper dump facilities, it’s pretty unsightly to see a hose hanging out draining into the grass all the time. Dump discretely for 20-30 minutes to drain the tank, then close the valve and stow the hose.
How do you treat gray water to reduce the smell?
There were a few times when the gray tank got really full that you could smell the gases, even with the back-flow preventer in place in our plumbing. As such, we purchased a product that reduces or mitigates the bacteria smell in the tank until it can be drained. You can find this gray water treatment on Amazon.
Our best practice to reduce the smell from the gray water tank in our
- Scrape as much food off the plates as possible to limit what goes down the drain.
- Treat the water with an environmentally-friendly deodorizer.
- Drain the gray water frequently to limit the risk of overflow and odor build-up.
You don’t need much of the product to reduce or remove the odor. Be mindful that you purchase something that is environmentally-friendly, especially if you are dumping your gray water somewhere other than a sewer.
Some say you can treat gray water with vinegar but don’t make yourself suffer like we did. Just skip straight for the deodorizer or drain more frequently.
Best Water Tank for a Skoolie
We recommend the largest water tanks you can install. We went with two 100 gallon tanks for fresh water and gray water storage.
[…] that the days of hunkering down for an overnight or two in Wal-Mart parking lots and refilling your water tanks at questionable truck stops are fewer and far between… unless that’s your vibe. […]