Maintaining a clean and healthy swimming pool requires more than just skimming debris and adding chlorine. One of the most critical aspects of pool upkeep is vacuuming, which ensures that dirt, algae, and other contaminants are removed from the pool floor and walls. However, pool owners often struggle with a simple but important question: what setting should the pool filter be on when vacuuming? The answer varies depending on your pool type, filtration system, and whether you’re dealing with algae or cloudy water. This article dives deep into the various pool filter settings, how to use them effectively during vacuuming, and tips for optimal pool maintenance.
Understanding Your Pool Filter: Basics and Types
Before determining the correct setting for vacuuming, it’s crucial to understand how your pool’s filtration system works. Pool filters are designed to remove debris and contaminates from your water. The three most common types of pool filters:
- Cartridge Filters – use a pleated polyester or paper element to trap debris and are easy to clean by hosing off the cartridge.
- Sand Filters – use sand as a filtration medium, and debris is captured as water passes through it. Cleaning involves backwashing.
- DE (Diatomaceous Earth) Filters – use a fine powder called DE, which coats grid elements to trap even the smallest particles. These also require backwashing and recharging of DE powder.
Each filtration system has its optimal vacuuming strategies, especially when it comes to manipulating the directional settings on your multiport valve (if applicable). The key to efficient vacuuming is using the right filter setting—especially when dealing with large volumes of dirt or cloudy pools.
How Pool Vacuuming Works With the Filter
When you connect a manual pool vacuum, it operates by drawing water through a hose connected to the skimmer or dedicated vacuum line. As water moves through the vacuum head, it picks up debris and dirt from the pool surface and sends it through the hose and into the filter system. Therefore, the filter setting during vacuuming directly affects whether the debris gets trapped and stays there or just circulates back into the pool.
Common Filtration System Settings
For sand and DE filters with multiport valves, you’ll typically find the following settings:
- Filter – the normal operating mode
- Backwash – reverses water flow to clean out the filter
- Rinse – clears lines after backwashing
- Recirculate – bypasses the filter (water is pumped directly back into the pool)
- Waste – sends water directly to the waste line (not back into the pool)
- Closed – no water flow at all
For cartridge filters—which typically don’t have a multiport valve—the only way to handle vacuum debris is through the pump system that connects directly to the skimmer or main drain.
Choosing the Correct Filter Setting for Vacuuming a Pool
The correct setting depends first and foremost on the type and amount of debris in your pool.
Standard Debris Vacuuming
For light to moderate dirt, dust, and leaves:
- Use: ‘Filter’ Setting – This is generally the recommended setting for regular vacuuming. In this mode, all debris collected by the vacuum passes through the filter media. It ensures that contaminants are removed from the circulation system, helping to maintain water clarity.
Using the filter setting is ideal when the water is clear, and you’re dealing with routine maintenance. You avoid introducing debris back into the pool, which could happen in other modes.
Vacuuming with Algae or Heavily Clouded Water
When you’re addressing a pool that has algae blooms or is cloudy due to imbalance or debris overload:
- Use: ‘Waste’ Setting – This setting allows dirty water to bypass the filter and head straight down the waste line. This is especially critical when the filter media—particularly sand or DE—could be overwhelmed by the amount of algae or fine debris, which could back up into the pool if sent through the regular filtration cycle.
However, be aware that using the waste setting removes a large amount of water from the pool, which can lead to a significant drop in the water level. Always monitor the water level so it remains at the optimal half-way point in the skimmer opening.
Vacuuming with a Cartridge Filter Pool
Cartridge filter pools do not have a multiport setting typically, but you have options:
- Continue Using ‘Filter’ Setting – Despite bypassing the main filtration chamber somewhat differently than with sand or DE filters, the vacuum debris still travels through the pump and into the cartridge filter system.
- Direct to Waste (If Applicable) – Some systems with auxiliary pump drains may allow plumbed waste lines. If available, this helps when vacuuming thick debris or algae without overloading the cartridge.
In such cases, remove and clean the cartridge much more often to ensure performance is maintained after an extensive vacuuming session.
Recirculate and Closed Settings: When to Avoid Them
While these are useful for other pool functions:
- Do Not Use ‘Recirculate’ Setting – This mode bypasses the filter entirely, meaning debris collected through the vacuum returns to the pool water. This is essentially useless when you want to clean your pool.
- Avoid ‘Closed’ Setting – Doing so will stop any flow of water, rendering the vacuum entirely inactive.
In short, avoid recirculate and closed when vacuuming the pool unless you’re planning to do something else, like adding chemicals without the filter running.
Step-by-Step Guide to Vacuuming Your Pool with the Correct Filter Setting
To ensure effective pool vacuuming and proper use of the filter system, follow these steps:
Step 1: Choose the Correct Filter Mode
Based on your pool and debris conditions, select:
- Filter for routine vacuuming
- Waste for algae/cloudy water situations
Also, inspect your multiport valve or plumbing system carefully to ensure the correct setting is applied.
Step 2: Prepare the Pool Vacuum System
Set up your manual or automatic pool cleaner correctly:
- Connect the vacuum hose to the vacuum plate and insert it into the skimmer.
- Ensure the vacuum head is properly connected with full sealing to prevent air leaks.
- Fill the hose with pool water before inserting into skimmer to avoid air locks in the system.
This primes the system and helps create proper suction for debris pickup.
Step 3: Start the Pump and Vacuum Properly
With everything connected, turn on the pump:
- Watch for consistent suction and monitor the filter pressure to identify system strain.
- Keep slow, deliberate passes across the pool floor to thoroughly collect debris.
- Check your filter’s pressure gauge—if it spikes significantly, it may be time for a backwash, especially after extended vacuuming sessions.
Step 4: Monitor and Adjust as Needed
Depending on the duration and intensity of pool vacuuming:
- If using the waste setting, watch the water level so it doesn’t drop below the skimmer intake.
- If using filter mode, check back into the water clarity—especially for algae—if the filter becomes overwhelmed.
- Backwash the filter after vacuuming if pressure increases beyond normal or if vacuuming was extensive.
Vacuuming Pool Best Practices by Filter Type
Let’s break it down by the specific filter types and how they should be handled during vacuuming:
Sand Filter Pool
- Use ‘Filter’ for routine maintenance
- Use ‘Waste’ when dealing with excessive algae
- Backwash after switching back to ‘Filter’ if considerable debris was processed
- Monitor pressure regularly—if pressure rises by 8–10 psi above the baseline, consider backwashing
Sand filters are most effective with proper grading and regularly maintained sand levels.
DE Filter Pool
- Stick with ‘Filter’ unless vacuuming heavy algae
- Use ‘Waste’ for heavy debris situations, but remember to recharge the DE afterward
- Inspect the grids—they can tear or become dirty, compromising filtering ability
- Backwash only as needed—excessive backwashing leads to loss of DE particles
DE filters offer the finest filtration but are also delicate. Vacuuming on filter mode is ideal for most homeowners.
Cartridge Filter Pool
- Always use the ‘Filter’ setting during vacuuming
- Remove and clean the cartridges more frequently after heavy cleaning
- Use a waste line if plumbed—sends heavy debris directly out
- Prefiltering is key—use a net to collect large debris before vacuuming
Cartridge systems often require more frequent physical cleaning but are lower energy than sand or DE systems.
What to Avoid When Vacuuming a Pool
Despite the straightforward nature of vacuuming, many pool owners unknowingly make mistakes that impact efficiency or damage equipment. Here’s what to steer clear of:
Wrong Filter Settings
Using ‘Recirculate’ or ‘Closed’ when you should be in ‘Filter’ or ‘Waste’ is a common mistake. As previously mentioned, these settings either push dirty water back into the pool or stop suction entirely, making vacuuming impossible.
Ignoring the Water Level
The waste setting can rapidly remove significant amounts of water. If left unchecked, the water level can drop below the skimmer, forcing your pump to run dry, which can harm it.
Not Cleaning the Filter After Heavy Use
If you’ve vacuumed algae-heavy or very muddy water into the filter and don’t backwash or clean it afterward, the system may become clogged, forcing it to work harder and wear down faster.
Rushing Through Vacuuming
Quick passes across the bottom reduce suction efficiency. Slow, methodical strokes will capture more debris and help reduce the number of times vacuuming is required.
Starting With Air-Filled Hoses
If the vacuum hose is full of air when connected, it can lead to vacuum loss, decreased suction, and pump priming issues. Prime the hose manually before connecting it to the skimmer to ensure optimal flow.
The Science Behind Filtration and Why Settings Matter
Filtration efficiency is a matter of physical and chemical properties. When water passes through a filter, it must do so at an appropriate rate for particles to settle and be absorbed into the media. For example:
- Sand filters work at a grit level of ~20–40 microns.
- DE filters can filter particles as small as 3 microns.
- Cartridge filters fall between DE and sand in efficiency at 10–20 microns.
When vacuuming, if the water flow rate is too fast or if particles bypass the system entirely (i.e., on waste or recirculate settings), these small particles remain suspended in the water, reducing clarity and increasing the burden on chemical systems.
In the case of algae, the spores can range from microscopic to visible. Using waste mode allows you to expel these microorganisms before they enter your plumbing or re-contaminate the pool from within the filter.
Real-Life Scenarios: Choosing the Right Setting for Different Pool Situations
Let’s look at real-world examples of how to choose your filter mode:
Scenario 1: Mid-Season Maintenance with No Visible Algae
- Debris Type: Dust, dead leaves, pollen
- Best Setting: Filter
- Why: You want to trap the debris efficiently without removing water from the pool.
Scenario 2: After a Heavy Wind Storm or Flood
- Debris Type: Heavy silt, soil, or windblown debris
- Best Setting: Waste
- Why: Cartridge, DE, or sand filters can easily be overwhelmed. Using waste prevents debris from staying in the plumbing.
Scenario 3: Post-Algae Treatment
- Debris Type: Dead algae, cloudy particles
- Best Setting: Waste
- Why: Dead algae is microscopic but also sticky. Using filter might cause it to cling temporarily but break loose again, re-clouding the water.
Scenario 4: Routine Clean-Up (Weekly or Bi-weekly)
- Debris Type: Light accumulation, no serious issues
- Best Setting: Filter
- Why: The regular filter setting captures all contaminants without unnecessary water loss or chemical imbalance.
Final Tips for Optimal Pool Vacuuming
To wrap up, here are proven tips to get the most out of your pool vacuuming routine while preserving your filtration system’s efficiency:
- Clean filter cartridges frequently—especially when dealing with heavy loads of debris
- Use a pool clarifier to help particles clump before vacuuming
- Skim lightly before vacuuming—removing floating debris makes floor vacuuming more efficient
- Run your pump longer after vacuuming to help circulate chemicals and remaining particles through the filter
- Use a quality vacuum—a worn-out vacuum head can reduce efficiency
Conclusion: Know Your Settings, Keep Your Pool Clean
The question of “what setting should the pool filter be on when vacuuming?” is a critical one for all pool owners. By understanding your filtration system—whether sand, DE, or cartridge—and choosing the appropriate setting for your specific situation, you ensure a clean, sparkling pool without unnecessary wear and tear.
Whether you’re performing routine vacuuming or tackling a post-storm cleanup, selecting the optimal filter mode—be it Filter, Waste, or another setting—will allow you to enhance your pool clarity, protect your equipment, and avoid having to repeat the process. So take the time to learn your system, and make filter setting decisions part of your core pool care routine.
Should the Pool Filter Be on Filter or Waste When Vacuuming?
When vacuuming a swimming pool, the filter setting you choose depends on the type of filter you have and the level of dirt and debris in the pool. For most routine vacuuming, especially when the water is relatively clear, the filter should remain on the “Filter” setting. This allows the filtration system to trap debris as you vacuum, preventing it from re-entering the pool water.
However, if the pool has a large amount of sediment or algae buildup that could clog the filter, using the “Waste” setting might be more effective. This option sends the dirty water directly out through the waste line, bypassing the filter. It’s important to monitor the water level when using this setting, as the pool water level will drop rapidly due to the direct drainage.
What Is the Difference Between the Filter and Waste Settings on a Pool Pump?
The “Filter” setting is the standard operating mode for your pool pump. It circulates water through the filter media—sand, cartridge, or D.E. (diatomaceous earth)—to remove contaminants before returning the cleaned water to the pool. This setting helps maintain clear and balanced water and should be used during regular pool operation and most vacuuming tasks.
In contrast, the “Waste” setting directs water from the pool directly out to the waste line, bypassing the filter completely. This is useful for quickly draining water or when vacuuming large amounts of debris that could clog the filter. While convenient, the waste setting drains pool water, so you may need to add water back afterward to maintain the proper water level in your pool.
Is It Better to Vacuum the Pool on Waste or Backwash?
Vacuuming on the “Waste” setting can be beneficial when dealing with heavy debris or algae because it removes the dirt directly from the pool system without passing it through the filter. However, using this setting causes the pool water level to drop significantly and should only be used when necessary to avoid unnecessary water loss and potential damage to the pump.
Backwashing, on the other hand, is not a setting you use while vacuuming but a process used after filtration to clean the filter itself. It’s typically used when the filter pressure rises 8–10 psi above its starting level. If you’re vacuuming and notice your filter is clogging quickly, it may be a sign that a backwash is needed afterward to restore proper filter function.
What Setting Should a Cartridge Filter Be On When Vacuuming?
For cartridge filter systems, it’s generally best to vacuum with the filter set to “Filter.” Cartridge filters are effective at removing fine debris and dirt from the water. Using the “Waste” setting is often not available on cartridge filter systems since they don’t have a multiport valve with a waste option. Therefore, you should vacuum through the filter and manually clean the cartridge if it becomes clogged.
If you have a system that allows using the waste setting, it may be beneficial in extreme cases of dirt and sediment. However, keep in mind that cartridge filters are not designed for extended waste cycles. It’s important to regularly inspect and clean the filter element after vacuuming to ensure continued efficiency and prevent long-term clogging or reduced water flow.
What Is the Best Pool Filter Setting for Vacuuming Algae?
When vacuuming a pool with algae buildup, the best approach depends on the severity of the infestation. For light to moderate algae, vacuuming on the “Filter” setting is acceptable. The filter will help capture and remove the algae particles from the water. However, it’s important to clean or backwash the filter more frequently afterward to maintain proper filtration performance.
In cases of severe algae blooms or when you’re doing a full pool cleanup, you may want to switch the filter to the “Waste” setting to prevent overwhelming the filter system. This will send the algae-infested water directly out of the pool, reducing the strain on your filter. However, this will also lower the water level, so you should be ready to refill the pool to maintain proper operating levels afterward.
Can You Vacuum a Pool on Recirculate?
The “Recirculate” setting on a pool filter bypasses the filter media and sends water directly back into the pool. While this can be useful for short-term circulation during chemical treatment or when the filter isn’t functioning, it is not recommended for vacuuming. Any debris vacuumed up will be sent back into the pool, defeating the purpose of cleaning.
Instead of using “Recirculate,” make sure the filter is either on “Filter” or, in heavy debris cases, “Waste” to ensure contaminants are removed from the pool. Using the correct setting not only makes the vacuuming process more effective, but it also helps protect your pool equipment and water quality during cleaning.
Why Is My Pool Still Cloudy After Vacuuming on Waste?
If your pool remains cloudy after vacuuming on the “Waste” setting, it may be due to several factors. While vacuuming on waste removes large debris directly from the pool, it doesn’t address fine particles that cause cloudiness. These may include dust, pollen, microscopic algae, or unbalanced chemicals. Proper filtration and water balance are still necessary to fully clarify the water.
Additionally, the filter may need backwashing or cleaning, especially if it was heavily used prior to switching to waste. If you also used algaecides or water clarifiers during cleaning, it may take additional time for all particles to settle or be removed. Running the pump continuously and testing and adjusting your chemical levels afterward can help restore clarity and ensure overall pool health.