100 Gallon RV Water Tanks – Big Capacity for Big Adventures
Whether you’re living the full-time RV life or gearing up for an extended boondocking trip, upgrading to a 100 gallon RV water tank can be a total game-changer. The extra capacity means fewer refill stops, more freedom to camp off-grid, and the peace of mind that everyone can shower without watching the gauge drop like a rock.
Browse our full range of large-capacity tanks in the 100-Gallon RV Fresh Water Tank Collection to find the perfect fit for your rig.
Why Choose a 100 Gallon Tank?
- Extended independence: Carry enough fresh water for a family of four for 5–7 days, even with regular showers and dishwashing.
- Reduced campground fees: Less need to pull into a full-hookup site just to fill up.
- Perfect for upgrades: Many Class A and large fifth wheels have the storage bays and frame strength to handle a tank of this size.
Top 100 Gallon & Similar-Size Tanks We Recommend
1. Space-Saving 100 Gallon RV Fresh Water Tank (81" × 26" × 11")
Need a slim profile that slides neatly into a basement compartment? Check out our 100 Gallon RV Fresh Water Tank – 81" × 26" × 11". At just 11" tall, it delivers massive capacity without eating up vertical storage.
2. Low-Profile 96 Gallon RV Water Tank (60" × 48" × 8")
If you’re tight on height but have plenty of floor space, the 96 Gallon RV Water Tank – 60" × 48" × 8" offers nearly the same capacity in an ultra-flat package that rides above or below the frame.
Installation Tips
- Plan the route: Measure your storage bay and map out the fill, vent, and outlet lines before ordering.
- Use proper supports: A full 100 gallon tank weighs over 830 lbs. Reinforce brackets and use food-grade straps.
- Vent adequately: A ⅜" or ½" vent line prevents vacuum lock and speeds filling.
- Sanitize before first use: Flush with a bleach solution, rinse thoroughly, and you’re good to go.
Maintaining a 100 Gallon RV Water Tank
Big tanks need a bit of TLC:
- Sanitize every 3 months or after long storage.
- Install an inline sediment filter to keep debris out of the tank.
- Drain completely when temperatures drop below freezing to prevent cracks.
Is a 100 Gallon Tank Right for You?
If you regularly boondock, travel with five or more people, or simply hate queueing at the water spigot, the answer is likely yes. Still unsure? Reach out to our parts pros—tell us your RV model and we’ll confirm weight limits, dimensions, and the fittings you’ll need.
Frequently Asked Questions
- How much does a full 100 gallon RV water tank weigh?
- Water weighs about 8.34 lbs per gallon, so a full 100 gallon tank tips the scales at roughly 834 lbs plus the tank weight.
- Can I replace two smaller tanks with one 100 gallon tank?
- Usually yes, as long as the combined footprint and weight distribution work with your frame and suspension. Check clearances and add cross-bracing if needed.
- Do I need a special pump for a 100 gallon tank?
- Most 12-volt RV water pumps handle larger tanks just fine. Focus on flow rate (3–5 GPM) and PSI (40–60) rather than capacity.
- How often should I clean a 100 gallon RV fresh water tank?
- Sanitize at least quarterly or after any period of non-use longer than 30 days to keep water tasting fresh and safe.
- What fittings come with your 100 gallon RV tanks?
- Our tanks include standard 1½" fill, ½" vent, and ½" outlet fittings molded in. Adapters for PEX or flexible tubing are available.
Ready to upgrade? Explore every size and shape in our 100-Gallon RV Fresh Water Tank Collection and hit the road with more water and less worry.
