What is Dishwasher Salt and Why Do I Need It?
Dishwasher salt is a coarse, granulated salt specifically formulated for use in dishwashers. Unlike table salt or sea salt, it is highly purified and free from additives like iodine or anti-caking agents that could damage your appliance. Its primary function is to replenish the ion-exchange resin within the dishwasher's built-in water softener. This system is vital for combating the effects of hard water, which contains high levels of dissolved minerals like calcium and magnesium. Without effective softening, these minerals build up on dishes, cutlery, and internal dishwasher components, leading to dullness, spots, and reduced cleaning efficiency.
The need for dishwasher salt is directly linked to the hardness of your local water supply. In areas with high water hardness, mineral deposits can quickly accumulate. These deposits not only leave unsightly marks on your glassware and crockery but can also cause significant damage to the dishwasher's heating element and spray arms over time. Using the correct dishwasher salt ensures the appliance's water softening system operates efficiently, preventing these issues and prolonging the life of your machine. It’s a small but significant component in maintaining optimal dishwasher performance and achieving consistently clean results.
- Regenerates the dishwasher's water softener.
- Prevents limescale buildup from hard water.
- Ensures sparkling clean dishes and cutlery.
- Protects internal components from mineral damage.
The Role of Water Hardness
Water hardness is measured in parts per million (ppm) or grains per gallon (GPG) of dissolved minerals, primarily calcium and magnesium. Most domestic water supplies contain some level of these minerals. When water passes through the dishwasher’s softener unit, the resin beads attract and trap the mineral ions. Over time, these resin beads become saturated, rendering the softener ineffective. This is where dishwasher salt comes in. When you add salt to the designated compartment, it dissolves to create a brine solution. This brine is periodically flushed through the resin bed, releasing the trapped minerals and recharging the resin beads so they can continue to soften the water. Without this regeneration process, the water remains hard, leading to the problems detailed above.
Dishwasher Salt vs. Dishwasher Detergent
It is crucial to distinguish dishwasher salt from dishwasher detergent (often found in tablet, powder, or liquid form). Detergent is formulated to break down food particles, grease, and stains. Dishwasher salt, conversely, is solely for water softening. While some multi-function dishwasher tablets claim to include salt and rinse aid, their effectiveness can vary significantly, especially in very hard water areas. For consistent protection against limescale and optimal cleaning, using dedicated dishwasher salt in its designated compartment is generally recommended. Adding table salt or other substances to the salt compartment can cause irreversible damage to the softener system, leading to costly repairs.
How Dishwasher Salt Works: The Science Behind the Shine
The magic behind dishwasher salt lies in its interaction with the water softener unit, an integral part of most modern dishwashers. This unit contains ion-exchange resin beads. As hard water flows through the softener, these resin beads attract and hold onto the positively charged mineral ions, calcium (Ca²⁺) and magnesium (Mg²⁺), effectively removing them from the water. This process is known as ion exchange.
As the resin beads capture more and more mineral ions, they become saturated and lose their ability to soften water. This is where the dishwasher salt is essential. When the dishwasher's control system detects that the resin is saturated (often indicated by a salt warning light), it initiates a regeneration cycle. During this cycle, a concentrated brine solution, made by dissolving the added dishwasher salt in water, is flushed through the resin bed. The high concentration of sodium ions (Na⁺) in the brine overwhelms the resin, forcing the calcium and magnesium ions off the beads and into the wastewater, which is then drained away. The resin is thus recharged with sodium ions, ready to soften water again. This continuous cycle ensures that your dishwasher always uses softened water for washing and rinsing.
Understanding the Ion-Exchange Process
At a chemical level, the resin beads typically start loaded with sodium ions (Na⁺). When hard water containing calcium (Ca²⁺) and magnesium (Mg²⁺) ions passes through, the resin has a higher affinity for these divalent ions than for the monovalent sodium ions. Thus, the calcium and magnesium ions displace the sodium ions, attaching themselves to the resin and releasing sodium ions into the water. The simplified reaction looks something like this: Resin-Na⁺ + Ca²⁺/Mg²⁺ → Resin-Ca²⁺/Mg²⁺ + Na⁺. During regeneration, the brine solution (a high concentration of Na⁺) reverses this process: Resin-Ca²⁺/Mg²⁺ + Na⁺ → Resin-Na⁺ + Ca²⁺/Mg²⁺ (which is then flushed away). This cycle is fundamental to preventing limescale.
The effectiveness of your dishwasher is fundamentally tied to its ability to manage water hardness, and dishwasher salt is the key component enabling this.
Signs Your Dishwasher Needs Salt
Several indicators suggest your dishwasher needs replenishing with salt. The most obvious is the dedicated salt warning light on the control panel, which illuminates when the salt reservoir is low. Beyond this, you might observe a deterioration in cleaning performance. Dishes may appear cloudy or have white, chalky spots, particularly on glassware. You might also notice a film on cutlery or an increase in limescale deposits around the door seals or on the internal surfaces of the machine. If you live in a hard water area and have noticed these issues, it is highly probable that your dishwasher salt supply is depleted or non-existent.
Where to Put Dishwasher Salt: Locating the Compartment
Locating the dishwasher salt compartment is usually straightforward, though its exact position can vary slightly between appliance models. Typically, you will find it at the bottom of the dishwasher tub, on the floor. It is often situated next to or integrated with the filter assembly. The compartment is usually a screw-top lid, often marked with a salt symbol (a salt shaker or a diamond shape) or the word 'SALT'.
To access it, you may need to remove the lower basket of dishes. Once the basket is out, look down at the floor of the dishwasher tub. You should see a round, often plastic, cap that you can twist or pull open. Ensure the dishwasher is empty of dishes and cutlery before attempting to fill the salt compartment to avoid any salt crystals entering the wash area directly, which could potentially damage the machine.
- Compartment is usually at the bottom of the tub.
- Often located near the filter assembly.
- Look for a screw-top lid with a salt symbol.
- Remove the lower basket for access.
Step-by-Step Filling Instructions
1. Empty the Lower Basket: Remove all dishes and cutlery from the bottom rack to gain clear access to the compartment.
2. Locate the Lid: Identify the salt compartment lid. It's usually a large, circular cap at the base of the dishwasher tub.
3. Open the Lid: Twist the lid counter-clockwise to unscrew it. Some lids may lift straight up after unlocking.
4. Fill with Salt: Place the funnel (often supplied with the dishwasher or with the salt packaging) into the opening. Slowly pour the dishwasher salt into the compartment until it is full. The compartment is designed to hold a significant amount of salt. Do not overfill; stop when the salt reaches the top of the opening.
5. Initial Water Fill: The compartment is designed to be filled with water first, then salt. If there is already water in the compartment, you can proceed with filling the salt. If it's empty, pour in fresh water until the compartment is full before adding the salt. This prevents salt from escaping into the main tub during the initial filling.
6. Close the Lid: Screw the lid back on securely, ensuring it is tightly sealed to prevent water from entering the salt reservoir during the wash cycle. A loose lid can lead to salt being released prematurely, potentially damaging the water softener.
7. Run a Short Cycle: It is advisable to run a short, empty rinse or wash cycle after filling the salt. This helps to flush away any residual salt crystals from the compartment and surrounding areas, and it allows the machine to begin the regeneration process.
Common Mistakes to Avoid
One common error is mistaking the rinse aid compartment for the salt compartment. The rinse aid dispenser is usually smaller and located near the door, often with a symbol resembling a sun or star. Never put salt in the rinse aid dispenser or rinse aid in the salt compartment. Another mistake is using regular table salt, which contains anti-caking agents and impurities that can clog the softener and damage the machine. Always use salt specifically labelled for dishwashers. Finally, ensure the lid is properly sealed after refilling; a loose lid is a frequent cause of salt leakage and subsequent damage.
How to Use Dishwasher Salt Correctly: Frequency and Amount
The frequency with which you need to refill your dishwasher salt compartment depends on several factors, most notably the hardness of your water and the capacity of your dishwasher's salt reservoir. Many modern dishwashers are equipped with a salt indicator light that illuminates when the salt level is low, taking the guesswork out of refilling. If your machine lacks this feature, a general guideline is to check and refill the salt compartment every 1-2 months, especially if you run your dishwasher regularly.
When refilling, the compartment should be filled almost to the top. The exact amount can vary, but typically a single refill uses between 1kg and 2kg of dishwasher salt. The purpose is to create a saturated brine solution when water is added, which is essential for the regeneration cycle. Do not worry about adding too much salt; the dishwasher’s system is designed to draw only the necessary amount for regeneration. The key is to ensure the compartment is full enough to create the required brine concentration and that the lid is securely fastened.
- Refill when the salt warning light appears.
- Check monthly if no indicator light is present.
- Fill compartment almost to the top.
- Use only dedicated dishwasher salt.
When to Refill: Indicators and Best Practices
The most reliable indicator for refilling dishwasher salt is the dedicated warning light on your appliance's control panel. This light is usually activated by a float mechanism or sensor within the salt reservoir that detects a low salt level. When this light comes on, it's time to add more salt. If your dishwasher does not have a salt indicator, you will need to adopt a more manual approach. Check the salt level by unscrewing the lid; if you cannot see or feel a good amount of salt at the bottom, it's time to refill. For those without an indicator light, a good practice is to unscrew the cap and look inside once a month. If the salt level appears low, refill it. This proactive approach helps prevent the build-up of limescale, even if the machine doesn't explicitly signal a problem.
How Much Salt to Add
When you refill, you should fill the compartment until the salt reaches the level of the opening. Use the funnel provided with your dishwasher or salt packaging to pour the salt in without spilling. It is normal for some salt to spill into the tub during the initial filling of the compartment with water and salt; this is why running a rinse cycle afterwards is recommended. The dishwasher's internal system will manage how much of this salt is used during each regeneration cycle. You don't need to measure; just ensure the compartment is sufficiently full to allow for saturated brine formation.
Always ensure the salt compartment lid is screwed on tightly after refilling. A loose lid can allow wash water into the salt reservoir, dissolving too much salt at once and potentially damaging the water softener.
The Role of Rinse Aid
While we are discussing salt, it is worth mentioning dishwasher rinse aid. Rinse aid is a liquid drying agent that helps water sheet off dishes and cutlery during the final rinse cycle, preventing water spots and streaks and promoting faster drying. It is dispensed automatically from a separate compartment, usually located next to the detergent dispenser. Unlike salt, which is essential for water softening, rinse aid is primarily for improving drying and the final appearance of dishes. While some all-in-one dishwasher tablets contain rinse aid, many users find that using a separate, dedicated rinse aid provides superior results, especially for glassware. It complements the work of the salt by ensuring a perfect finish.
Troubleshooting Dishwasher Salt Issues
Experiencing problems with your dishwasher's performance can often be traced back to issues with the salt compartment or its contents. Common problems include the salt warning light remaining illuminated even after refilling, or seeing excessive limescale deposits despite regular salt usage. These issues can stem from simple oversights or more complex blockages within the salt system.
If the salt warning light stays on, the first thing to check is that the lid is screwed on tightly. Sometimes, a faulty sensor or a blockage preventing the sensor from registering the salt level can also be the culprit. If you've refilled and the light persists, try running a full, hot wash cycle to allow the machine to register the new salt level. If the light still doesn't go out, consult your appliance manual or contact the manufacturer. For excessive limescale, ensure you are using dedicated dishwasher salt and that your water hardness level requires the use of salt. It is also possible that the salt compartment itself or the water softener unit is blocked, preventing effective regeneration.
- Persistent salt light? Check lid and run a cycle.
- Limescale? Verify salt type and water hardness.
- Blockages can prevent regeneration.
- Consult manual for sensor issues.
Salt Warning Light Stays On
This is a frequent troubleshooting query. After refilling the salt compartment, the warning light should extinguish after the next wash cycle, or sometimes immediately. If it remains lit:
- Check the Lid: Ensure the salt compartment lid is fully screwed on and sealed. A slightly loose lid might not activate the sensor correctly.
- Sensor Obstruction: The salt sensor might be obstructed by a piece of debris or old salt residue. Gently clean around the sensor if accessible.
- Faulty Sensor: In some cases, the sensor itself may be faulty, requiring professional diagnosis or replacement.
- Low Salt Level: Double-check that you actually added enough salt. The compartment should be filled near the top.
- Initial Regeneration: It can take one full wash cycle for the machine to complete its initial regeneration process and recognise the new salt level.
Dishes Still Coming Out Cloudy or Spotted
If you are using dishwasher salt and still finding spots or cloudiness on your dishes, particularly glassware, several factors could be at play:
- Water Hardness vs. Salt Usage: Ensure your water hardness level actually requires dishwasher salt. If your water is only moderately hard, and you are using an all-in-one tablet that contains some salt, it might be insufficient. Conversely, if your water is very hard, you may need to top up the salt more frequently or use a higher-quality salt.
- Rinse Aid Level: Cloudiness can also be a sign of insufficient rinse aid. Check the rinse aid indicator and refill the compartment if necessary. Rinse aid is crucial for drying and preventing water spots.
- Blocked Salt Compartment/Softener: Over time, the salt compartment or the water softener unit can become clogged with salt residue or limescale. This prevents the brine from being correctly formed or circulated. You might need to manually clean the salt compartment and potentially descale the entire system.
- Detergent Issues: Ensure you are using the correct amount and type of dishwasher detergent.
If your dishwasher has a setting for water hardness, ensure it is adjusted correctly to match your local supply. This setting influences how often the machine regenerates the salt and how much rinse aid it dispenses.
Salt Spills and Damage
Spilling salt inside the dishwasher tub during refilling is common. While a small amount is usually not a major issue as it will be washed away, significant spillage, especially if left for an extended period or if the lid is not sealed, can cause corrosion. The high sodium content in salt can damage stainless steel interiors and components over time. Always clean up any substantial salt spills promptly and ensure the lid is securely fastened before running the dishwasher. If you suspect salt has entered the wash cycle improperly or caused damage, it is best to run several empty hot cycles and inspect the interior for any signs of corrosion.
Dishwasher Salt vs. Other Salt Types: What to Avoid
It might seem intuitive that any form of salt could work in a dishwasher, but this is a critical misconception that can lead to expensive appliance damage. Dishwasher salt is a highly specialised product, and using alternatives like table salt, sea salt, rock salt, or even coarse cooking salt can have detrimental effects on your machine's performance and longevity.
The primary reason for using dedicated dishwasher salt is its purity and grain size. Dishwasher salt is typically 99.9% pure sodium chloride (NaCl) and is manufactured with a coarse, irregular grain. This specific formulation is designed to dissolve slowly and evenly within the salt reservoir, creating the concentrated brine solution needed for the water softener's regeneration cycle. It’s engineered not to compact or clog the intricate mechanisms of the softener unit. Using other salt types can introduce impurities and additives that can cause blockages, corrosion, and ultimately, failure of the water softening system.
- Only use salt specifically labelled for dishwashers.
- Table salt contains anti-caking agents harmful to the machine.
- Impurities in other salts can cause blockages and corrosion.
- Dedicated salt dissolves correctly for regeneration.
Why Table Salt is Not Suitable
Table salt, whether fine or coarse, is iodised and contains anti-caking agents (like calcium silicate or magnesium carbonate). The iodine is unnecessary for dishwashing and can potentially leave residue. More importantly, the anti-caking agents are designed to prevent salt from clumping in your kitchen. However, in a dishwasher's salt reservoir, these agents can dissolve unevenly, form a paste, or clog the fine mesh of the softener's resin bed and the dispensing mechanism. This prevents proper brine formation and regeneration, leading to ineffective water softening and subsequent limescale build-up. The added minerals and impurities in table salt can also contribute to corrosion over time.
Sea Salt and Rock Salt: The Dangers
Sea salt, while often seen as a more natural alternative, can also contain a variety of trace minerals and impurities beyond pure sodium chloride. These can have the same clogging and corrosive effects as the additives found in table salt. Rock salt, often used for de-icing roads, is typically very impure and may contain heavy metals or other contaminants that are not only harmful to your dishwasher but could also be a health concern. Its grain size may also be unsuitable, leading to inconsistent dissolution or blockages. For these reasons, they are strictly not recommended for use in dishwashers.
Using the wrong type of salt is one of the most common, yet avoidable, causes of damage to a dishwasher's critical water softening system.
What to Look for in Dishwasher Salt
When purchasing dishwasher salt, look for packaging that explicitly states 'Dishwasher Salt' or 'Rinse Aid Salt'. Reputable brands will ensure their product is pure sodium chloride, free from additives, and with a suitable coarse grain size. The packaging may also mention that it is specifically formulated to regenerate the ion-exchange resin in dishwashers. While brands like Finish, Somat, Ecover, or Smol offer their own versions, the key is the purity and formulation, not necessarily the brand name, though established brands are more likely to adhere to strict quality controls. Always check the ingredient list or product description to confirm it is pure sodium chloride intended for this specific appliance use.
The Link Between Dishwasher Salt and Rinse Aid
Dishwasher salt and rinse aid are two distinct, yet equally important, consumables for achieving optimal cleaning and drying performance from your dishwasher. While salt tackles the fundamental issue of water hardness by regenerating the appliance's internal water softener, rinse aid focuses on the final stages of the wash cycle: rinsing and drying. Understanding their separate roles helps in diagnosing performance issues and ensuring you use your dishwasher effectively.
Salt works within the water softener unit to remove calcium and magnesium ions. This process prevents limescale build-up on dishes, cutlery, and the dishwasher's internal components. Without adequate salt, water remains hard, leading to spots, streaks, and a dull finish. Rinse aid, on the other hand, is a liquid agent dispensed during the final rinse. It reduces the surface tension of water, causing it to 'sheet' off surfaces rather than form droplets. This sheeting action helps dishes dry faster and prevents water spots and streaks, leaving glassware and crockery sparkling clean.
- Salt softens water; rinse aid aids drying.
- Salt prevents limescale; rinse aid prevents spots.
- Both are essential for optimal results.
- Dispensed from separate compartments.
How Rinse Aid Works
Rinse aid is a surfactant, meaning it lowers the surface tension of water. During the final rinse cycle, the hot water is sprayed onto the dishes. If the water has high surface tension, it forms small droplets that cling to the surfaces. As these droplets evaporate, they leave behind mineral deposits from the water, resulting in spots and streaks. Rinse aid, added in small quantities, causes the water to spread thinly and evenly over the surfaces, forming a continuous film that drains away completely. This prevents the formation of individual droplets and thus eliminates the cause of water spots and streaks, leading to a much shinier and drier finish. The dispenser for rinse aid is usually located on the inside of the dishwasher door, often adjacent to the detergent dispenser, and typically has an indicator light for when it needs refilling.
Can I Use All-in-One Tablets?
Many dishwasher tablet brands offer 'all-in-one' or '3-in-1' (or even '10-in-1') formulations that claim to contain detergent, rinse aid, and salt. These can be convenient, especially for those who prefer minimal fuss. However, their effectiveness, particularly regarding salt and rinse aid, can be variable. The amount of salt and rinse aid in these tablets is pre-set and may not be sufficient for areas with very hard water or for specific wash cycles. In such cases, using dedicated dishwasher salt and rinse aid in their respective compartments, even when using all-in-one tablets, can significantly improve results. It is often recommended to use separate salt and rinse aid if you notice spots, streaks, or poor drying, even when using these multi-function tablets. Check your dishwasher manual for advice on using these products with your specific model.
If you notice your glasses are coming out cloudy or spotty, even when using rinse aid, try increasing the dosage setting on your rinse aid dispenser. Most dispensers have an adjustable dial for this purpose.
When to Use Both Salt and Rinse Aid
You should use dishwasher salt if your local water supply is hard. Most of the UK has moderately hard to very hard water, so using salt is generally recommended. The salt compartment should be refilled as needed, typically indicated by a warning light. Rinse aid should be used if you notice water spots or poor drying performance. Refill the rinse aid dispenser when its indicator light comes on, or if you see a decline in drying results. For most households in hard water areas, using both dedicated dishwasher salt and rinse aid provides the best combination for sparkling dishes and a well-maintained appliance. While all-in-one tablets offer convenience, they may not always provide the targeted performance that separate, high-quality dishwasher salt and rinse aid can deliver, especially in challenging water conditions.
Maintaining Your Dishwasher for Peak Performance
Regular maintenance is key to ensuring your dishwasher operates efficiently and lasts for years. Beyond simply refilling the salt and rinse aid compartments, a few simple practices can make a significant difference to its cleaning power and longevity. These include cleaning filters, checking spray arms, and occasionally running a cleaning cycle to tackle grease and limescale build-up.
A well-maintained dishwasher not only cleans your dishes better but also consumes less energy and water. Neglecting maintenance can lead to reduced performance, increased energy bills, and the need for premature repairs or replacement. By incorporating a few simple checks and cleaning routines into your schedule, you can keep your appliance in prime condition, ensuring sparkling results with every wash. This proactive approach saves time, money, and frustration in the long run.
- Clean filters regularly to prevent blockages.
- Check spray arms for debris.
- Run cleaning cycles periodically.
- Address limescale build-up promptly.
Cleaning the Dishwasher Filter
The filter system at the bottom of the dishwasher tub is designed to catch food particles and debris, preventing them from recirculating and causing blockages or unpleasant odours. This filter needs regular cleaning, typically once a month or more frequently if you notice reduced cleaning performance. Most filter systems consist of a coarse outer filter and a fine inner filter. To clean them:
- Locate the filter assembly at the bottom of the dishwasher tub.
- Twist and remove the filter components.
- Rinse them thoroughly under warm running water, using a soft brush to remove any stubborn food residue.
- Reassemble and replace the filters securely.
Failure to clean the filter is a very common reason for poor washing results, as dirty water is recirculated, leaving food particles on dishes.
Checking and Cleaning Spray Arms
The spray arms, which rotate to distribute water jets, can become clogged with food particles or limescale. Blocked spray arms mean water cannot be distributed evenly, leading to ineffective cleaning. Periodically, inspect the small holes in the spray arms. If they appear blocked, use a toothpick or a needle to gently clear any debris. Some spray arms can be removed for easier cleaning. Ensure they spin freely after cleaning.
Regular checks of filters and spray arms are fundamental to maintaining a dishwasher's ability to clean effectively, directly impacting the quality of your results.
Running a Cleaning Cycle
Over time, grease, soap scum, and limescale can build up inside the dishwasher, affecting its performance and potentially causing odours. To combat this, you can run a cleaning cycle using a commercial dishwasher cleaner or a simple home remedy like white vinegar. For a vinegar cycle:
- Place a dishwasher-safe bowl filled with 1-2 cups of white vinegar on the bottom rack of an empty dishwasher.
- Run a hot, long wash cycle.
- The vinegar will help to break down grease and descale the internal components.
Alternatively, use a dedicated dishwasher cleaning product, following the manufacturer's instructions. Running such a cycle every 1-3 months can help keep your dishwasher running smoothly and smelling fresh.
Frequently Asked Questions About Dishwasher Salt
Here are answers to some common queries about using dishwasher salt. Understanding these points can help you get the best performance from your appliance and ensure its longevity.
What does dishwasher salt do?
Dishwasher salt is specifically designed to regenerate the ion-exchange resin in your dishwasher's built-in water softener. It dissolves to form a brine solution that flushes out the accumulated calcium and magnesium minerals from the resin, preventing limescale buildup on dishes and the appliance itself.
What is dishwasher salt?
Dishwasher salt is a highly purified, coarse-grained sodium chloride. It is free from additives like iodine or anti-caking agents found in table salt, which could damage the appliance's water softening system and cause blockages or corrosion.
What does salt in dishwasher do?
The salt in a dishwasher works with the water softener to remove hard minerals from the water. This process is essential for preventing limescale deposits, ensuring dishes come out clean and spot-free, and protecting the internal components of the dishwasher from damage caused by mineral build-up.
What is salt for in a dishwasher?
Salt is used in a dishwasher to maintain the effectiveness of its water softening system. By regenerating the ion-exchange resin, it ensures that the machine consistently uses softened water, which is crucial for optimal cleaning performance and preventing the long-term effects of hard water, such as cloudy dishes and internal damage.
What does salt do in a dishwasher?
Salt in a dishwasher initiates a regeneration cycle for the water softener. It dissolves to create a brine that flushes away mineral deposits (calcium and magnesium) that have been trapped by the resin beads, thereby recharging the resin to continue softening the water effectively for subsequent wash cycles.
Do I need dishwasher salt?
You need dishwasher salt if your local water supply is hard. Most regions in the UK have hard water, meaning it contains significant mineral content. Using salt is essential in these areas to prevent limescale, improve cleaning results, and protect your dishwasher from damage. Check your local water hardness or look for signs like cloudy dishes.
Do you need dishwasher salt?
Yes, you generally need dishwasher salt if you have hard water. The salt is a key component for the dishwasher's water softener to function correctly. Without it, minerals build up, leading to spots on dishes, reduced cleaning efficiency, and potential damage to the appliance over time. Relying solely on all-in-one tablets may not be sufficient in hard water areas.