HandymanFix Optimal: Install FLUIDMASTER DUOFLUSH without wasting water | dual flush conversion system
Optimal: Install FLUIDMASTER DUOFLUSH without wasting water | dual flush conversion system
Did you know that if you are not careful, converting a single flush system to a dual flush system could actually waste more water? Using our optimal installation guide, we show you how to measure your water so that you can save the most water. We spent a lot of time on the adjustment because if each person flushes 6 times daily, that is 2000 flushes a year per person.
The installation instructions from the manufacturer aren’t the best. First, it didn’t discuss how to adjust the blue clamp on the refill valve. Second, adjustment for the half flush from this manufacturer may require you to waste too much water before finding the right point on the dial. We provide the optimal Golden Section solution to waste a minimal amount of water while testing.
If you decide to purchase the real dual flush kit, here are couple of links for the products:
for Fluidmaster DUOFLUSH Fluidmaster DUOFLUSH
for Danco Dual Flush: Dual Flush by Danco at Amazon
People who are accustomed to the single flush system may accidentally push the lever down when they intended to half flush. Since liquid waste is more frequent than solid waste, pushing down the lever by mistake would cause more water waste. In this video we provide one simple solution to swap the half dial and the full dial.
Since different viewers may have different questions in mind, here are the timestamps so that you can click and skip to the sections you’re interested in:
The Golden Section algorithm description:
https://youtu.be/m6C1YULrPCU?t=126
Swapping the half dial and the full dial:
https://youtu.be/m6C1YULrPCU?t=749
Duoflush installation:
https://youtu.be/m6C1YULrPCU?t=255
Flush valve dial adjustment:
https://youtu.be/m6C1YULrPCU?t=413
Refill Valve installation:
https://youtu.be/m6C1YULrPCU?t=805
The blue clamp on the refill valve adjustment:
https://youtu.be/m6C1YULrPCU?t=879
What to do if the dial adjustment is out of range:
https://youtu.be/m6C1YULrPCU?t=525
If you have the “dual flush” system from Danco, you can watch this video:
Save Water: Convert Toilet into Dual Flush, Best Install, Explanation & Tips
A few toilet or plumbing related issues can be found below:
Slow Draining: Easy 5 Seconds Toilet Flush Test and Solving the Slow Flush Mystery
5 Different Ways To Make Your Toilet Use Less Water
Toilet siphon effect, when plunger, auger and snake fail:
Big Mystery of the Adjustable Toilet Flapper Solved
5 Ways To Unclog Toilet Using A Garden Hose
How To Unclog Bathroom Sink
How To Unclog Kitchen Sink
https://twitter.com/RealGeniusAsian/status/1085646599416508417
Alternative Methods
Toilet modification for water savings has several approaches.
1. Adjustable Flapper Valve
When to use: Fine-tuning flush volume on a standard toilet without replacing the fill valve.
- Pros: Inexpensive, adjustable dial controls water per flush, universal fit for most toilets
- Cons: Adjustment can be finicky, rubber degrades over time, may not seal well on older flush valves
- Difficulty: Easy
- Estimated cost: ~$5-10
2. Toilet Tank Bank or Fill-Cycle Diverter
When to use: Reducing water use without modifying any components.
- Pros: Simply displaces water in the tank (tank bank) or diverts excess fill water (diverter), no tools needed
- Cons: Minimal savings (0.5-0.8 gallons per flush), does not change flush mechanics
- Difficulty: Easy
- Estimated cost: ~$2-5
3. Replace with a WaterSense-Certified Toilet
When to use: When the toilet is old (3.5-7 gallons per flush) and modifications are insufficient.
- Pros: Uses 1.28 gallons or less per flush, better bowl wash, may qualify for utility rebates
- Cons: Full toilet replacement cost and labor, old toilet disposal
- Difficulty: Medium to Hard
- Estimated cost: ~$100-400 for the toilet plus installation
Always verify contractor licensing and insurance in your state. Cost estimates are averages and may vary by location.