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How To Increase GPF On Toilets? [5 Easy Methods]

It becomes incredibly frustrating when your toilet doesn’t have enough GPF. These low-flow toilets are supposed to save money and help the environment. But they lack flushing power. In the end, double flush defeats the purpose.

Increasing the GPF (Gallons Per Flush) on a toilet would mean using more water per flush, which is generally not recommended for water conservation and environmental reasons. In modern times, there is a focus on water efficiency, and many regions have regulations that mandate low-flow toilets with lower GPF values to conserve water.

If you are looking to increase the flushing power of your toilet, it’s better to focus on improving the toilet’s performance rather than increasing the GPF. Here are some ways to do that:

  1. Check the flush valve and fill valve: Ensure that these components are functioning correctly and not obstructed. Faulty or partially blocked valves can hinder proper flushing.
  2. Clean the toilet jets and rim holes: Mineral deposits and debris can build up over time, affecting the flow of water during flushing. Regularly clean the jets and rim holes to maintain efficient flushing.
  3. Adjust the water level: Most toilets allow you to adjust the water level in the tank. Make sure it is set to the manufacturer’s recommended level for optimal performance.
  4. Replace worn-out parts: If your toilet is old or has worn-out components, consider replacing them with newer, more efficient parts.
  5. Consider a high-performance toilet: If you’re looking for a more powerful flush, consider upgrading to a high-performance toilet model that meets modern water efficiency standards while still providing better flushing performance.

Remember, it’s essential to strike a balance between flushing power and water conservation. Increasing the GPF might result in more water usage without actually improving flushing effectiveness.

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How to increase GPF on toilets?

You can’t actually convert your low-flow toilet into a high-flow toilet; however, you can increase its flushing power. Things like raising the tank float or cylinder float, unclogging the toilet or repairing or replacing the flush valve are all great ways to make your flushes more effective.

Understanding GPF

Before we can offer tips on improving the GPF (or Gallons Per Flush) we should understand what it is. GPF is the amount of water a toilet uses to flush out waste. Different toilets have different GPF ratings, with older models typically using more water than newer ones. The average GPF for a toilet is 1.6, but some models can use as much as 3.5 gallons per flush and as little as 1.2 gallons. Understanding your toilet’s GPF is important before attempting to increase it.

Increasing your toilet’s GPF can help improve its flushing power and reduce the number of times you need to flush, saving water in the long run.

Here are some ways to increase your toilet’s flushing power.

How To Increase GPF On Toilets? [5 Easy Methods] 1

5 Methods To Increase GPF on Toilet

Your toilet having low GPF is one of the most annoying situations. Modern low-flow toilets flush around 1.2-1.6 gallons per use. You might find a stamp on the lower side of the toilet. It will indicate the amount of water your toilet uses per flush. 

If it shows 1.6 gallons per use that signifies low flow. Besides, you can recognize the toilet is low flow if you bought it in recent years. 

Maintaining regular bathroom cleaning is the main key. This way you can increase GPF on toilet flush power. If you want a high-flow toilet, regularly wash your toilet. Anyway, there are some methods that’ll help you to resolve low GPF immediately.

Method 1: Elevate the Tank Float

To address the issue of low flow in your toilet, you can follow these steps to elevate the tank float:

  1. Begin by inspecting the tank float. Take a look inside the tank and observe the water level.
  2. If the float level appears too low, it is likely causing the low flow.
  3. Locate a screw positioned between the float and the valve inside the tank.
  4. Using a screwdriver, slowly turn the screw. As you do so, the float will rise, and the water level will increase accordingly.
  5. Stop adjusting the screw when you are satisfied with the water level. The raised water level will enable the tank to flush more water with each toilet use.

Method 2: Adjust the Cylinder Float

To enhance your toilet’s performance, you can adjust the cylinder float by following these technical steps:

  1. Locate the cylindrical-shaped cylinder float positioned at the center of the toilet tank.
  2. Identify the thin adjustment stem connected to the cylinder float, which extends into the fill valve.
  3. Use your hand to pinch the release clip attached to the adjustment stem. If necessary, employ a screwdriver to facilitate the movement.
  4. Turn the screwdriver in a clockwise direction to raise the cylinder float. Continue turning until it reaches the appropriate height.
  5. Use the screwdriver, applying gentle force as needed during the adjustment process.

This is a similar technique to replacing grohe thermostatic shower valve, if it has issues.

Method 3: Clean Out Toilet Flush Holes

Understand that flush holes allow water to fill the toilet during each flush. Over time, these holes can become clogged, resulting in reduced flushing efficiency.

To address weakened flushing caused by clogged flush holes, it is necessary to clean them thoroughly using the following steps:

  1. Put on gloves to protect your hands during the cleaning process.
  2. Obtain a small, narrow tool such as a bobby pin or a similar implement.
  3. Insert the tip of the tool into the flush holes and carefully remove any obstructions or buildup by gently poking and maneuvering the tool.
  4. Additionally, consider using an acidic toilet bowl cleaner to further dissolve any mineral deposits or stubborn residue that may be obstructing the flush holes.

When using acidic toilet bowl cleaner, always follow the manufacturer’s instructions and safety precautions. Ensure proper ventilation in the bathroom while using the cleaner, and avoid direct contact with the skin or eyes. Rinse the toilet thoroughly after using the cleaner.

There are several brands of acidic toilet bowl cleaners available in the market. You can explore various options to select a suitable cleaner from the provided list of products, keeping in mind the safety guidelines.

Super Blue Mild Acid Toilet Bowl Cleaner 
GENUINE JOE Acid Bowl Cleaner 
Misty Secure Hydrochloric Acid Bowl Cleaner
Jani-Source BellaBowl Clinging Acid Bowl Cleaner
Zep Acidic Toilet Bowl Cleaner

Try to clean the holes on a regular basis and treat them with chemicals. Chemicals clean the holes from the depth and protect flush power. Regular cleaning will keep your toilet more powerful after unclogging flush holes.

Method 4: Unclog the Toilet

Clogging is a common issue that can impede water filling in toilets, leading to reduced flushing power or GPF rate. It is important to address this problem promptly to restore optimal functionality. Clogs can occur deep within the toilet drain, affecting water flow and flushing performance.

To resolve this issue, several tools can be utilized for unclogging the toilet, including plungers, drain snakes, enzyme treatments, or products like Drano.

Among these tools, plungers and drain snakes are particularly effective in eliminating toilet clogs. By vigorously plunging the toilet approximately 10-12 times, most obstructions can be dislodged. Enzyme cleaners can also be applied to the drain to dissolve blockages.

Furthermore, it is worth noting that clogs tend to develop over time. Therefore, it is advisable to take preventive measures by regularly maintaining the toilet to prevent clogging issues from arising.


Regardless of any claims made on the packaging, it is crucial to understand that “flushable wipes” are NOT truly flushable. Here’s why:

  1. Non-biodegradable materials: Flushable wipes are typically made from non-biodegradable materials such as polyester or plastic fibers. Unlike toilet paper, which breaks down easily in water, these wipes do not disintegrate quickly.
  2. Resistance to water: Flushable wipes are designed to be durable and resistant to tearing, allowing them to withstand moisture and stay intact. While this durability may be beneficial for their intended use, it becomes problematic when flushed down the toilet. Instead of breaking down, the wipes can clog pipes, leading to costly plumbing issues.
  3. Interference with sewage systems: Flushing “flushable wipes” can have severe consequences for sewage systems. These wipes can accumulate and combine with other debris, forming blockages in pipes and pumps. This can result in sewer backups, overflows, and environmental pollution.
  4. Impacts on wastewater treatment plants: Wastewater treatment plants are not designed to effectively process and break down flushable wipes. These wipes can get caught in filtration systems, leading to equipment malfunctions and increased maintenance costs.

To avoid these problems, it is essential to dispose of wipes, even those labeled as “flushable,” in the trash bin instead of flushing them down the toilet. By doing so, you can help prevent plumbing issues, protect the environment, and maintain the proper functioning of sewage systems and wastewater treatment plants.

Method 5: Repair flush Valve

The flush valve creates a seal with tight suction. It helps the toilet to flush each time. Yet, sometimes this seal becomes loose or damaged. As a result, it causes weak flushes or no flush at all.

When the seal of the flush valve becomes loose and cannot be adequately repaired, replacing the flush valve is necessary.

Increase GPF on Toilet

Here’s a step-by-step guide on how to replace the flush valve:

  1. Shut off the water supply: Locate the water shut-off valve behind or near the toilet and turn it clockwise to shut off the water supply. Flush the toilet to drain the water from the tank.
  2. Remove the tank lid: Lift off the tank lid and place it in a safe location.
  3. Drain the tank: Use a sponge or towel to soak up any remaining water in the tank. This will prevent water from spilling when you disconnect the flush valve.
  4. Disconnect the water supply line: Unscrew the nut connecting the water supply line to the bottom of the tank using an adjustable wrench. Place a bucket or towel beneath to catch any water that may still be in the line.
  5. Remove the flush valve locknut: Locate the locknut on the underside of the tank that holds the flush valve in place. Use a pair of pliers or an adjustable wrench to loosen and remove the locknut.
  6. Take out the old flush valve: Lift the old flush valve assembly out of the tank. This may require some twisting or maneuvering to release it from any remaining sealant or gasket.
  7. Install the new flush valve: Take the new flush valve assembly and position it into the opening at the bottom of the tank. Ensure that the rubber or foam gasket on the bottom of the flush valve fits snugly against the tank.
  8. Secure the flush valve: Place the locknut over the flush valve tailpiece and tighten it by hand. Then, use pliers or an adjustable wrench to give it a final snug fit. Be careful not to overtighten, as it could damage the tank.
  9. Reconnect the water supply line: Attach the water supply line to the fill valve at the bottom of the tank and tighten the nut securely using an adjustable wrench.
  10. Turn on the water supply: Slowly turn the water shut-off valve counterclockwise to restore the water supply to the toilet tank. Check for any leaks around the flush valve and water supply line.
  11. Test the flush: With the tank refilled, flush the toilet a few times to ensure that the new flush valve is working correctly and creating a proper seal.

Replacing the flush valve should help resolve the issue of a loose seal and restore the proper functioning of your toilet’s flushing system. If you are unsure about any step or encounter difficulties, it is recommended to consult a professional plumber for assistance.

See? It’s not that tough to increase the GPF of your toilet. Plus it definitely took less time than the time for retiling a bathroom

These are all ways to increase GPF and efficiency of your toilet. Try them out and let us know if you see an improvement in your flushing capabilities!


Question: How do I know if my toilet is low flow?

Answer: You can identify if your toilet is low flow by checking the stamp on the toilet. Check stamp on the lower side of the seat. When it shows 1.6 GPF, that means it’s a low-flow one.

Question: Which is better 1.28 or 1.6 GPF?

Answer: Toilets with a 1.28 GPF rating are more water-efficient than those with a 1.6 GPF rating, resulting in significant water savings and supporting sustainable water usage. However, it’s important to choose a toilet that balances water efficiency with sufficient flushing performance.

Question: How can you reduce the amount of water flushed?

Answer: One way to save water and reduce the amount flushed is by placing a plastic bottle filled with water and pebbles inside the toilet tank. The weight of the bottle reduces the water volume in the tank, resulting in less water being flushed with each use.

Bottom Line

In conclusion, improving the performance of your toilet does not necessarily require increasing the GPF (Gallons Per Flush). Instead, focus on maintenance and optimization techniques to enhance flushing power. Elevating the tank float, adjusting the cylinder float, cleaning the flush holes, unclogging the toilet, and repairing the flush valve are effective methods to increase flushing efficiency. Remember to prioritize water conservation and choose a toilet that balances water efficiency with adequate flushing performance.