How To Clean Your Pool Liner Without Draining (and Get Rid of Pesky Stains!)

Having a swimming pool is so much fun for both kids and adults. However, when it comes to maintenance and cleaning, it’s not that much fun anymore.

Vinyl-lined swimming pools are the most common type of pools and the easiest to clean. Depending on the stain type, you’ll just need a few tools and products to make the maintenance less of a burden.

There are a few tips that will make it easier for you to keep your swimming pool spotless. Keep reading to find out how to clean a pool liner without draining.

We’ll also review ways to remove stains from the pool and prevent them from coming back.

What Is a Swimming Pool Liner?

A swimming pool liner is a vinyl surface that covers the walls and floor of the swimming pool. It comes in all different colors and designs to suit your taste. 

Aside from giving a cool look to your pool, vinyl liners help keep the water in and prevent leaks. The best part is that it’s extremely durable and highly affordable after factoring in a 10-15 year lifespan. 

Liners can also reduce the growth of algae, fungus, and bacteria in the pool due to their smooth surface.

How To Clean Pool Liner Without Draining?

Pool liners get dirty for different kinds of reasons, including the surrounding environment. This is especially true if you don’t clean and skim them regularly.

Swimming pools are exposed to all kinds of contaminants, such as dust, dirt, pollen, insects, leaves, grass clippings and other unwanted items. 

Over time, pool liners accumulate stains and build-up, which don’t look pleasant and can be difficult to remove.  These can be caused by imbalanced chemistry in the water, including high mineral and metal levels.

Considering that draining your vinyl-lined pool can pose irreversible damage to the lining, here are the steps to clean your pool liner without having to drain it:

Step 1 – Skim

Remove all of the leaves and debris with a skimming net. Also, take time to clear the skimmer basket from any collected items on a regular basis.

Step 2 – Scrub, Scrub

For this step, you’ll need to use a pool brush attached to a telescopic pole. A telescopic pole is an extendable handle that can be used with many extensions, such as skimmer nets, vacuum heads, and pool brushes.

• Use a pool brush with nylon bristles.  Avoid metal bristles as this will damage your liner.
• Start with brushing the walls and floor of your vinyl pool liner to loosen algae and grime

Although liners are durable, care must still be taken while brushing.  Avoid using excessive force that could cause damage.

Step 3 – Remove Stains

The methods used to remove stains from pool liners vary depending on the type of stain and what caused it.  Take appropriate steps described later in the article for stain treatment.

Step 4 – Vacuum

Use a vacuum head attached to a telescopic pole that’s specifically made for pool liners. Vacuum the floor of the pool to remove any sunken debris.

Most vacuums utilize the skimmer as a source of suction, but there are alternative ways to vacuum without a skimmer.

Routinely backwash your filter, especially after vacuuming up lots of debris.

Step 5 – Balance and Shock

Check your pool water chemistry balance with a test kit once a week. Mostly, you’ll need to test the water for:

• Free Chlorine (FC): Helps sanitize your pool water. Too much FC can irritate your eyes and skin as well as fade the color of your pool liner. The proper amount of FC is dependent on your cyanuric acid (CYA) level.
• Total Alkalinity (TA): Total alkalinity helps your pool water resist the change in pH levels. It’s the first thing you should check and balance in your pool water. Keep Total Alkalinity levels at 80 – 120 ppm.
• pH levels: It’s a measure of how acidic your pool water is. Unbalanced pH levels can damage your pool. Keep pH levels at 7.2 – 7.6.
• Calcium Hardness: Too much calcium will cloud the pool water, accumulate scaling on the walls, and damage your pool equipment. Keep Calcium Hardness at around 150 – 200 ppm.
• Cyanuric Acid (CYA): Protects pool water from UV light that might burn the chlorine away faster.  Too much CYA will render the chlorine ineffective.  Keep the Cyanuric Acid levels at 40 – 80 ppm.

How to Remove Stains from Pool Liner Without Draining

The methods used to remove stains from vinyl pool liners vary depending on the type of stain and what caused it.  Here’s how you can remove pool stains without draining the water.

Organic Stains

Usually, organic stains are greenish or brownish.  As the name suggests, they’re caused by organic matter, such as mud, bugs, leaves, or algae. 

Sometimes it may not be completely evident whether the stain is organic or something else, such as metal.  To easily figure this out, you can hold a chlorine tablet on the stain to see if it disappears –if it does, then it’s an organic stain.

How to Remove Algae Stains from Vinyl Pool Liner

Getting rid of algae stains on a vinyl liner is easily accomplished without draining the pool:

• After the pool has been brushed, add enough chlorine to raise the free chlorine (FC) in the pool to near shock level
• Run the pump 24/7 after adding the chlorine 
• Brush the pool frequently to continue loosening any organic matter

After the stains are gone you can return the pump back to its normal schedule.  You can also allow chlorine levels to fall back to their normal range.

Keeping chlorine at proper levels will also help prevent a spontaneous algae outbreak in the pool.

Metal Stains

Metal stains are harder to clean than organic ones and vary in color depending on what kind of metal caused them. 

Metals can enter the pool depending on the source of fill water used.  Well water is often more likely to contain traces of metal than city water; however, even city water can be a source of metal stains.

Here are some visual cues that can help you determine which metal is causing your stain:

• Iron: reddish-brown color
• Copper: Bluish-green color
• Manganese: Blackish-purple color

You can also determine if the stain is metal-based by rubbing a vitamin C tablet on a stained portion of the liner.  If the stain is metal, it should either disappear or change color.

Additionally, you can test the water with a metal test kit to better confirm the metal type.  

How to Remove Metal Stains from Vinyl Pool Liner

Most metal stains can be removed through acid.  Commercial products exist, but common household acids can also be used.

For smaller areas of staining, you can spot treat as follows:

1 – Place crushed ascorbic acid (Vitamin C) in a sock

2 – Tie a loose knot at the top of the sock

3 – Rub the sock around the stain until it disappears

For larger stains that cover the liner, the following steps can be used:

1 – Lower the chlorine of the pool to 0 ppm either waiting for it to naturally fall or using a chemical, such as Sodium Thiosulfate.  This will allow the acid to be most effective.

2 – If desired, add an algaecide to the pool to prevent algae growth while chlorine level is low.

3 – Add one of the following acids by pouring around the edge of the pool:
+ Ascorbic Acid: ½ pound per 10,000 gallons
+ Citric Acid: 1 pound per 10,000 gallons
+ Commercial Metal Stain Remover: Dosage per instructions

4 – Run the pump for at least an hour to allow circulation of the acids.

5 – Repeat acid addition as needed if stains have not visibly lifted.

6 – Add a metal sequestrant to bind to the lifted metals

7 – Run the pump 24/7 

8 – Return pH to around 7.2

9 – Return the pump to normal schedule

10 – Return chlorine levels to normal range

11 – Monitor for stains, add more sequestrant if stains start reappearing

Unless you have a greensand filter that can remove the dissolved metals, the metals will continue to remain in the pool.  However, periodic addition of sequestrants in the pool will help prevent the metals from re-staining.

How to Remove Manganese Stains from Pool

If you have manganese stains in the pool that do not resolve with acid treatment, you may need to shock your pool.  High levels of chlorine can cause the manganese to oxidize and precipitate to the bottom of the pool.  

After the manganese has precipitated, you can vacuum it out.  Just ensure you backwash and clean the filter afterwards as manganese tends to gunk up the filter.  

How to Prevent Metal Staining of Pool Liner

While greensand filters are great at removing metal from the pool, it’s not always practical for most pool owners.  

Fortunately, there are other ways to prevent metal staining of the pool.  We’ll run through them to help keep your liner free from stains:

1 – Metal Filter for Hose

If your source water contains metal, you can filter it out before they even get into your pool.  There are various hose filters you can purchase that will remove iron, copper and other metals as you add water to the pool.

These filters are useful to use anytime you add water to the pool.  The filters are generally rated to last up to a specified number of gallons, so choose a size that’s appropriate for you.

2 – Metal Filter for Pool

If your pool water contains metals, you can consider a metal filter such as the CuLator Ultra 4.0.  This filter sits in your pump basket or skimmer, and will remove metals from the water as it flows through.  

These filters require replacement periodically in order to maintain maximum effectiveness.

3 – Water Softener

Some pool owners have water softeners plumbed to their fill line as a means to prevent metal stains.  A water softener can remove iron, calcium and magnesium.  

Depending on how much water you’re adding, it may require frequent regeneration cycles of the softener along with significant salt usage.

It’s recommended that you maintain a Calcium Hardness (CH) of about 150 ppm.  If using a softener, it may be necessary to add calcium chloride to the pool to increase the CH.

4 – Sequestrant

If you have metals in your pool water, you can use a commercial metal sequestrant to keep them from forming stains.  

The sequestrant should be added periodically in order to keep the metals dissolved.  Just know that if you stop adding the sequestrant, the metals may start to re-form stains.

5 – Avoid Copper Algaecides

While algaecides can be useful to keep algae from taking over the pool, some of them contain copper.  The copper is known to be effective at killing algae.

Look for algaecides without copper in order to avoid unsightly staining of your liner.

6 – Avoid Chlorine Tablets with Copper

In some cases, copper is added to chlorine tablets to help prevent algae.  Unfortunately, this copper can produce stains in your pool.

If looking to avoid stains, you may want to seek out alternative chlorine tablets.

7 – Drain & Refill with Metal-Free Water

If you have metals in your pool and want to stop using sequestrants or other commercial products, you may want to consider going through a drain and refill process.

Before draining, you’ll want to lift the stains using the acid process described earlier.

For vinyl-lined pools, it’s important that you do not fully drain the pool, so it may take several times of partially draining and refilling to achieve metal-free water.  Alternatively, you can seek professional support to see if it’s possible to fully drain the pool followed by a quick refill.

During this process, you’ll want to ensure the refill water does not contain unwanted metals such as iron or copper.  You can perform a metal test of your supply water to ensure it’s clear, or use a metal filter on the hose as needed.

So, Why Not Drain?

It’s strongly discouraged to drain your vinyl-lined pool unless you want to replace the liner.  Draining your pool may cause the liner to pop out of place or could cause unsightly wrinkles once refilled.  

Even if you need to fix a puncture in your pool liner, you won’t have to drain it as most pool liner repair kits are designed to work underwater.

When the liner is freshly installed and the pool is filled, the plasticized vinyl will stretch a bit under the weight of the water. Over time, the vinyl becomes harder and loses elasticity.

As a result, if you drain the pool, the liner will shrink back to its original size. Shrunken and hard, when refilled with water, the vinyl won’t stretch back to pool size. Consequently, this will cause it to tear or detach from the pool body.

How To Maintain Pool Liner

Maintenance is the best way to avoid hard stains and buildup, as well as keep the water clean and safe for all swimmers. Below are some tips to help you maintain your pool liner.

1 – Keep it clean: make sure to skim the water regularly. In addition, brush the walls and floor of your pool liner with a soft-bristle brush at least once a week to keep dirt and debris from accumulating.

2 – Cover your pool: if not in use, keep your pool covered to protect the pool liner from the sun, prevent weathering, and keep the dirt out.

3 – Clean waterline: wipe the waterline with a sponge regularly to avoid buildups caused by oils and dirt.

4 – Check your chemicals: always check and maintain chemicals and pH levels.

5 – Never fully drain the pool: to avoid damage, you should never fully drain a vinyl-lined pool.

6 – Check for damage: periodically check for any tears and rips in your liner and repair them using patching glue or adhesive repair patches.

7 – Get rid of wrinkles: wrinkles can make it difficult to keep the pool clean.  A plunger can be used to move the wrinkles towards the nearest wall.  

Final Takeaway

Even though swimming pools need regular maintenance, cleaning them guarantees a refreshing, enjoyable, and relaxing outdoor activity for all family members during the summer.

When it comes to cleaning your vinyl-lined pool, determining the cause and having the right tools is definitely a plus. Although removing stains can be challenging, there are multiple methods that you can try out. With a little effort, your pool will be as good as new.

Also, take care when using chlorine around surrounding surfaces such as pool enclosures in order to avoid accidental damage.

Happy (clean & clear) Swimming!