Inground Pool Liner Care Guide is pleased to provide the following inground pool liner care and maintenance information to you courtesy of Kafko Manufacturing.

Proper Care and Maintenance of Pools With Inground Pool Liners

Your vinyl lined pool requires periodic maintenance and proper care to keep the liner surface soft, clean and the pattern colors vibrant. After the pool liner has been installed and water and chemicals have been added, it is important to regularly care for your pool so the water will stay safe and healthy and the pool liner will last for many years to come.


Water Chemistry

Proper water balance is the single most important factor to maximizing the life and appearance of any swimming pool and pool liner. The following table shows ranges for basic water chemistry.








Free Chlorine



Total Alkalinity

80-120 ppm


Calcium Hardness

200-300 ppm



35-60 ppm



PH Levels

PH is the measurement of acidity of water - measured on a scale of 0 to 14 with 7 being neutral. A pH below 7.0 means the water is very acidic, as the pH approaches 8.0, the water becomes very basic (alkaline).

Not only do proper pH levels allow the other chemicals to do their work, but it is important to note that low and high levels can cause damage to a vinyl liner. Under the right circumstances with pH below 7.0, the liner can actually grow and develop unsightly wrinkles. High pH greatly accelerates the aging process and shortens the life of the liner.

Chlorine is much less effective at higher pH levels. At a pH of 8.0; chlorine is only 22% effective.

Total Alkalinity

Alkalinity is a measuring of the alkaline materials dissolved in water. With the alkalinity in the range of 100 to 150 PPM it helps pH to resist fluctuations. If the alkalinity is low the result is "pH bounce" in and out of range.

Calcium Hardness

Calcium Hardness refers to the amount of dissolved minerals in water. A low hardness can lead to corrosion of pool surface, filter, heater, ladder, ect. A calcium hardness level that is too high causes cloudy water and scaling (white chalky appearance).

Chlorine Stabilizer (100% Cyanuric Acid)

Stabilizer acts as a sun shield to extend the life of chlorine up to 3 1/2 times. It actually holds the useful form of chlorine in the pool water until needed giving longer protection against bacteria and algae. It leaves no residue - 100% soluble. "Stabilized" chlorine products (sticks - tablets - chlorine powder) contain some cyanuric acid which helps to maintain the proper level throughout the season.

Adding stabilizer: With clean pool - backwash filter. Make a slurry of stabilizer and water, then add very slowly through the skimmer with the pump running continuously for at least 48 hours. Do not backwash for 3 or 4 days after adding stabilizer. sells E-Z Chlor Save stabilizer.

Using Trichlor Sanitizer With Pool Liners

DO NOT add trichlor to a floating dispenser and ALWAYS continuously run the water circulation system 24 hours a day during the pool season when Trichlor is used.

It should be understood that the absorption of water is a function of the PVC. However, the absorption will not take place with proper care. It should also be understood that the affects of the chemicals on the vinyl are cumulative and irreversible. Remember, less is best when adding chemicals to your vinyl liner pool.

  • DO NOT allow the pH of the pool to drop below 7.4.  **Range 7.4-7.8.
  • DO NOT allow chlorine levels to exceed 3 ppm using Trichlor sanitizer.
  • DO NOT shock or super chlorinate your vinyl lined pool  with Trichlor. Alkaline sanitizer (hypochlorite products) should be used.
  • DO NOT continuously heat your vinyl lined pool to  temperatures above 82 degrees Fahrenheit. Hot water will dissolve Trichlor sanitizer at a faster rate making the water very aggressive to the vinyl liner.
  • DO NOT allow true total carbonate alkalinity to drop below 90 ppm when acidic Trichlor is used as the sanitizing agent. Alkalinity range 90-125 ppm.
  • DO NOT forget to correct for cyanuric acid level when measuring true total alkalinity. True total alkalinity equals measured total alkalinity minus one third measured cyanuric acid level.

Failure to limit and control cyanuric acid level could result in the following:

  • Low alkalinity
  • pH drop or bounce when Trichlor is added
  • Increased chlorine demand (more Trichlor is needed)
  • Aggressive water
  • Bleached and/or wrinkled vinyl liner


Testing Pool Water

  • Follow test kit instructions (test strips are easier to use than kits)
  • Use fresh reagents - shelf life for liquid reagents is only one year.
  • Rinse out test cell with pool water before using.
  • Retrieve water sample at elbow depth from deep end of the pool

A number of influences can bring out rapid shifts in the pool's pH These include:

  • Rain
  • Swimmer wastes
  • Refill water
  • pH of various pool chemicals:



pH Level


pH 11.7


pH 13


pH 3.6


pH 6.0


pH 10.5


pH 2.9


pH 2.0



Why Is The Water In My Inground Pool Cloudy?

Contaminants buildup: When swimmer wastes and other contaminants build up, the result is "combined chlorine". Shock the pool!!! recommends using Burst Shock to avoid bleaching your liner.

Chemical residue: Using a calcium hypochlorite shock can result in a residue build up and cloudy water. If the water looks like chalk or milk, it is usually the result of using a lot of calcium hypochlorite shock. To use this type of shock, especially in vinyl liner pools to prevent bleaching of the liner, you must:

  • Fill a bucket about 1/2 full of water
  • Add Shock - do not stir - let sit for a few minutes - pour only the liquid into the pool
  • Discard the residue
  • Do not try to dissolve the residue

Water Out of Balance: A high pH, high Total Alkaline or High Calcium Hardness will cause cloudy water. Test the water!!

Symptoms of Out of Balance Pool Water:

    • Eye and skin irritation
    • Staining
    • Unsightly wrinkles in vinyl liners
    • Interferes with the efficiency of sanitizers
    • Corrosion of metals (pump seals, heaters, lights, etc.)
    • Cloudy water
    • Scale build up (white chalky appearance) on pool surface as well as inside filter and heater
    • Pitting and corrosion of gunite/concrete pools

Algae: Algae is a possible cause of cloudy water. We have more information on algae below.

Poor Filtration: Is the filter system running a significant number of hours every day? During the swim season, the filter needs to run a minimum of 10 to 12 hours daily.

How to Treat Cloudy Pool Water Or Algae


Adding Water Balance Adjustment Chemicals

It is best to pre dissolve a water balance adjustment chemical in a plastic bucket of pool water. Then add to the deep end of the pool or in front of a return with the pump running.

  • pH Adjustment: Add recommended dosage, wait several hours and test water again.
  • Alkalinity: Add at the rate of 5 lbs or less; wait about 10 minutes between each 5 lbs.
  • Hardness: Add at the rate of 5 lbs. Or less; wait 30 minutes between each 5. If large amounts of calcium are needed, add over several days.




Low pH and High Alkalinity

Adjust Alkalinity first, then
  the next day adjust pH

High pH Low Alkalinity

Adjust pH first, then the
  next day adjust Alkalinity

Low pH and Low Alkalinity

Adjust pH first, then the
  next day adjust Alkalinity

High pH High Alkalinity

Adjust Alkalinity first, then
  the next day adjust pH



It is not uncommon to find metals, often called free metals, dissolved in pool water. Usually they come from source water, sometimes they come as a result of the erosion of metal pool fixtures, such as heater cores.

Free metals in pool water can cause staining of pool surfaces and inhibit the performance of water sanitizers. Ideally, there should be no metals in the water: 0 ppm. If metals are detected in your water you will need a sequestering agent to render them harmless.

How to treat metals in pools with pool liners: The presence of metals in the water such as iron (reddish-brown), copper (blue-green) or manganese (brown-red) can cause cloudy water. To remove the metals:

  • Add 1 quart flocking agent
  • Add 1 quart clarifier
  • Run filter 1 hour; turn off overnight
  • Vacuum to waste
  • When pool is completely clear, add a stain & scale preventer to remove any stains


Algae In Inground Pools with Pool Liners

Mustard Algae: Common algae in pools appears yellow-brown or "mustard" colored. It brushes off the walls of the pools easily, but quickly returns. It often rows in shady areas with poor circulation. It resists chlorine and shock treatment.

Solution: Use an algaecide along with chlorine shock. Follow label directions. Place all vacuum equipment - hose, head, pole, brushes, etc. into pool during treatment Maintain a higher than normal chlorine reading for 4 to 5 days after treatment.

Green Algae: Green algae is one of the most common problems for pools. It usually appears in corners or other areas where circulation is poor. Once established, green algae can grow explosively.

Solution: Use algaecide along with chlorine shock.. Follow label directions. It is also recommended to use a flocking agent, always vacuum to waste or drain (not backwash).

Black Algae: A very resistant form of algae that clings to the pool's walls, floor, and cracks. The longer black algae are present, the longer it will take to get rid of it. Black algae can actually pit the mar cite finish in a gunite pool. Treat black algae as soon as it is detected. Black algae are usually found in gunite/concrete pools.

Solution: Brush algae spots vigorously with a stiff algae brush and pour algaecide along the sides where spots are visible. Use an algaecide specifically developed for black algae. Run filter continuously for one hour, and then add chlorine shock to the pool. Turn off filter and leave off for several days.


Preventing Algae



Brush walls and pool floor


Vacuum pool


Use a maintenance dose of Algaecide


Use a maintenance dose of Majestic Blue


Maintain a proper chlorine reading


Keep properly balanced - Free Chlorine:1.0-2.0, pH:7.2-7.6, Total Alkalinity:80-120ppm,   Hardness:200-300ppm, Stabilizer: 35-60ppm



Opening Your Inground Pool

Opening your pool signals the start of warm weather and relaxed attitudes. Whether you're emerging from a long snowy winter or a quick brush with cooler temps, opening your pool can be a simple process.

  • Remove leaves and debris from pool cover.
  • Take off the cover, clean it, and store it.
  • Hook up pool pumps and filters and reconnect all hoses and electrical connections.
  • Remove leaves and debris from skimmers, filters, pumps and drains.
  • Take out leaves and debris from the pool.
  • Fill pool water up to proper level.
  • Turn on the filter pump and make sure all skimmers, bottom drains, and filters are functioning properly.
  • Vacuum up any remaining debris in the pool.
  • After pool filter has been running 3-4 hours, test the water. Retest water to see if any adjustments have to be made.
  • Once adjustments have been made, shock the pool following label directions.

Closing and Winterizing Your Pool

Whether you live in the sunbelt or the snowbelt, closing your pool correctly is an important and easy process that will elongate the life of your pool.

Cold Climates

  • Adjust pH to 7.2-7.8 to prevent stains, scaling and algae growth. Shock the pool using label directions.
  • Run the filter for 24-48 hours.
  • Remove floating debris and vacuum thoroughly.
  • Add an algaecide to prevent algae from forming before water freezes.
  • Follow your pool manufacturer's directions for lowering your water level. Only a few pools need to be completely drained during the winter. Many pools fare cold temperatures better when partially filled with water as a buffer. A drained pool can also crack or pop out of the      ground because of pressure from ground water.
  • Shut off filter pump and drain pump, filter heater and all other equipment. Store to prevent freezing. Follow manufacturer's directions for lubrication and proper covering(s).
  • Turn off all power to the support equipment and remove fuses or turn the circuit breakers to off.
  • If you have a slide or diving board, take it off and store it.
  • Cover pool securely and fill water bags halfway (the edge of the cover should be sealed so that wind does not get under it). A quality winter cover resists water, weather and pool chemicals and keeps out leaves and airborne dust. sells a wide selection of quality pool covers.

Mild Climates

Your weather permits a longer swimming season. However, if there will be many weeks when your pool is not in use, continue routine maintenance on a reduced schedule.

  • Begin by reducing filter running time in half. Keep pH between 7.2-7.8 and free available chlorine between 1.0 and 3.0 parts per million (use tester). Follow pool equipment manufacturer's instructions for proper care of equipment during this time.
  • If you do not cover your pool, clean your skimmer every week, maintain filter according to manufacturer's instructions. Vacuum as needed.
  • Covering your pool will keep out leaves and dirt and reduces the number of needed chlorination. Before covering, shock treat      according to manufacturer's directions.


Pool Equipment Maintenance for Pools With Inground Liners

Your filtration equipment, automatic cleaners, diving boards, slides, and other pool equipment need periodic maintenance, too. Please review the instructions and warranty information that came with your equipment or visit the manufacturer's website for additional details.


Something Is Wrong With My Inground Pool Liner

Staining and Discoloration

The most common cause of staining and discoloration of your liner below the water line is secretions by micro-organisms. As these micro-organisms feed, they secrete dyes, which can be one of many colors that stain the vinyl. Although these stains are unsightly, they in no way degrade the performance of the vinyl. These dyes are compatible with the plasticizers in the vinyl, causing the stains to go all the way through the sheet. There is no proven method for removing these stains.

There is a common misconception that the microbial resistant additives used in pool liners will kill the micro-organisms in the area adjacent to the liner. Many people believe that there is a "protective zone" near the liner that will not support life. This is not the case. The additive in the vinyl prevents the vinyl from supporting life but in no way does it prevent life in areas adjacent to the liner. Extreme care must be taken during installation to insure that there is nothing behind the liner that may become a food source for these organisms.

There have been cases of stains forming in pools soon after the installation of a replacement liner when there was never a problem with the original liner. Although there is no way that we can say for sure what has happened behind that new liner, it is believed that when the environment behind the liner is exposed to light and oxygen a "rebirth" or micro-organisms takes place. If the bottom and sidewalls of the pool are not properly treated, there is a chance that problems may arise.

There can also be changes in the ground water that introduce organisms into an area that had not been previously exposed. Extended periods of heavy rains will often cause significant changes in the microbiology of the ground water. Whenever there is a change in the environment around your pool, there is an opportunity for micro-organisms which hitherto were not present to move into the ground water, thereby creating the possibility of staining.

Bacteria and Fungus Stains In Pool Liners

Some types of bacteria and fungus found in the soil can actually penetrate through a vinyl liner and cause stains to appear on the liner. Usually they will start off as spotted or cloud-like formations on the liner. Algaecides used in the pool water have little if any effect on the stains caused from bacteria, since it doesn't get to the source of the bacteria in the soil. If a pool is known to have a problem with bacteria staining the liner, the ground underneath the liner may be treated with a solution of one half household chlorine bleach and one half water. Mix the bleach in the water and mist the floor of the pool with a small garden sprayer three or four times prior to dropping the new liner in the pool. After the last application of bleach solution, wait several hours before dropping the liner; making sure the solution has been absorbed into the ground.

If the liner has been recently replaced, one method which has been used several times is the use of Copper Iron Sulfate (FeSO4) to change the pH of the soil around the pool, therefore killing off the source of the bacteria or fungus. This is not a guaranteed cure in all cases but in the last few years it has had some astonishing results for some of our customers. Best of all, this can be tried without having to drain the pool and replace the liner! Copperas Iron Sulfate is a chemical used by tree nurseries for treating the pH of soil for some iron deficiencies in plants. For an average size pool, say an 18 x 36 rectangle, you need about twelve to fifteen pounds of this powered chemical. Sprinkle it on the ground next to the pool deck on as many sides of the pool as possible. Then turn a lawn sprinkler on the ground for two or three days, long enough to get the ground around the pool thoroughly saturated with water. The idea is to get the powder to soak deep into the ground so it can change the pH of the soil and hopefully kill off the source of the bacteria. Usually results are not seen for a week or two since it has to get deep in the ground to have any effect on the bacteria. The Copper Iron Sulfate has not been known to have any harsh effects on grass and care should be taken when using around delicate flowers.

Pool Liner Wrinkling

Our vinyl manufacturer has invested a great deal of time and money into discovering the causes of and the prevention of wrinkling. Wrinkles that develop in swimming pool liners after installation are caused by the vinyl absorbing water and thereby changing dimensions. Testing has shown that high levels of chlorine or bromine will initiate excessive water absorption into the vinyl liner and lead to wrinkles. Low pH and cyanuric acid stabilizer are also factors in wrinkle formation because the activity level of the chlorine is affected by pH and stabilizer level.

Our experience has shown that the use of trichloroisocyanuric acid sanitizer (Trichlor) and low pH levels can cause wrinkling of your vinyl liner. Non- chlorine sanitizer systems have been found to be safer to use with vinyl liners.

Deterioration and Dry Rot

In most cases, these three problems are different stages of the same phenomenon. The cause of these problems are many and varied, but have a universal theme. In most cases, the discoloration (usually brown), the deterioration (stiffening of the vinyl) and then the complete failure of the vinyl, commonly referred to as "dry rotting", is due to the extraction of the plasticizers and stabilizers from the vinyl. (Plasticizer is the additive which gives the vinyl its flexibility, stabilizers give the vinyl its high temperature stability.) Under normal circumstances, the volatility of these additives is very low and the vinyl will maintain its physical characteristics for many years.

Experience has taught us that under certain circumstances the area above the water line can begin to deteriorate very quickly. There are three main contributors to this problem; chemical attack, high temperatures and UV rays. The UV resistant characteristics of pool vinyl is excellent and by itself the UV rays do not present a significant problem. However, acid based vinyl cleaners, when not rinsed completely from the vinyl, exposed to extremely high temperatures and the effects of UV rays, will accelerate deterioration of the vinyl liner. There are however, certain steps that can be taken to combat these problems.

We had found, through laboratory testing, that acid based vinyl cleaners will adversely affect the life of the vinyl. Exposure to sun light and high temperatures will greatly accelerate that deterioration process. From a vinyl standpoint, we do not recommend using any cleaners that contain acid. If you do use an acid based cleaner, you must rinse all traces of the cleaner from the vinyl. If you do not remove all traces of the cleaner, you are creating a situation where accelerated breakdown of plasticizer and stabilizer will take place, thereby significantly shortening the life of the liner. Use alkaline based cleaners. They are more vinyl friendly and they work just as well as the acid based cleaners. In all instances, rinse the liner fully.

Clean your pool often by taking a soft cloth and using the pool water to rinse contaminates from the vinyl liner. Substances such as body oil, sun tan lotion, baby oil, etc., will collect at the line. These substances, when exposed to the sun and the high temperature that can be found just above the water line, will often times turn brown and be very difficult to remove from the pool liner.

If it is an option, have at least a two foot radius, or larger, corners in your pool. This will lessen the stress put on the vinyl in the corners. Insist that the liner fit properly. Watch the installation of the liner. If it has to be "stretched in", insist on a looser fitting liner. If the liner is too small it will tend to pull away from the wall above the waterline and especially in the corners. On the sun side of the pool, temperatures can reach in excess of 180 degrees Fahrenheit, between the liner and the sidewalls. These areas that pull away are the areas that generate the highest temperatures and are the places that will fail first. Remember: Stressed vinyl is more susceptible to chemical and environmental attack.

With proper cleaning and a properly fitted liner, there is no reason why your liner should not last many years. However, unless you follow these simple rules, your liner's life will be significantly shortened.

Pattern Flaking Off

To understand why the pattern may flake off, there must be a basic understanding of the procedures involved in the printing of your pool liner. The print pattern is applied by a process called "roto-gravure" printing. The inks used are solvent based and when applied to the vinyl they actually bond themselves to the vinyl by "biting" into the it. Then a clear "top coat" is applied to increase abrasion resistance and provide an added layer of UV protection.

The cause of ink flaking off the vinyl is low water PH. An acidic environment will weaken the bond by softening the coating and eventually the ink. The more acidic the environment the greater the likelihood of damage. The effect is cumulative and irreversible. Once this softening occurs, the coating and ink are susceptible to abrasion and flaking.

Always keep your pool at the recommended PH of 7.4 to 7.8. Deviation from these levels will adversely effect the performance of your liner.


Repairing Your Inground Pool Liner

Life happens. We have heard the stories about pole vaulting in the pool or using the pool as a practice green for pitching golf balls. The great thing about the liner is that if it does sustain a puncture or tear, it can usually be easily repaired with a simple patch kit. First, let’s talk about finding a leak in a pool, then we will discuss repair.

Find A Leak In My Swimming Pool Liner

The proper method is to follow a step by step procedure of elimination. Before starting the leak procedure, make sure you do not have an obvious leak at the equipment pad or end of the backwash line. Look for unusual wet spots around the pool. Visually inspect the liner for a tear. Using a swim mask, visually check each of the seams on the liner for integrity. Pay special attention to where two seams cross or in the corners of geometric shapes. Make a game for the kids and have them examine the liner. If nothing is found, move to step 1.

Determine the amount of water loss to confirm a leak. It’s possible to lose more than 1” of water in a short period of time if the pool is getting a lot of use with many swimmers splashing about. Temperature inversion, wind, and humidity can also cause rapid evaporation of up to 3/8” a day. To establish the amount of water loss, place a bucket of water in the pool on your steps. Fill the bucket with pool water until it is level with the pool water level. Mark the water level on the inside and outside of the bucket and recheck levels 12, 24, and 36 hours later. Do this when the pool is receiving little or no use. If the pool level is falling below the level in the bucket by more than ½” in 12 hours, then you probably have a leak.

We need to eliminate plumbing leaks as a source of the water loss. Turn off the equipment, plug the inlets and skimmers, mark the water level, and keep swimmers out for 24 hours. Recheck in 24 hours. If the leak stops, you may need to have a professional repair company pressure test and repair the lines. If you are still losing water at the same rate as before, you should move to step 3.

Actually, you can begin this step at soon as the equipment has been turned off. We are going to test the various gaskets where the liner has been cut. Do this with a small squeeze bottle filled with water and food coloring. The Phenol red test solution bottle will also work. Starting at the step and with the water still, slowly squeeze the colored water within 1” of the side of the step flange. Begin on one side of the step flange and work around the bottom to the other side. If the gasket is leaking, you will notice the colored water being drawn towards the opening. If a leak is found and it is not a tear, simply retightening the screws may solve the problem. Actually, it is a good idea to retighten the screws anyway. If no leak is found at the step, move to the next cut out and repeat the procedure. All cutouts with flange and gaskets should be checked, including inlets, skimmers, and lights. The colored water should also be squeezed around the light to check for leaks in the back of the light niche. It may be necessary to remove the light to fully test the niche. Make sure you “dye” test the main drain if possible.

If no leak has been found and the pool is still leaking, you may need to let the water leak down until it stops. If it stops just below a cutout, re-inspect the fitting, gasket, and faceplate for damage. Retighten the screws. Visually inspect the liner within 1” of the water level all around the pool. Add a couple inches of water to the pool and see if the leak has been fixed. Do not let the pool leak down below the shallow end. If the pool continues to leak to near the shallow end, it may be necessary to call a professional to find the leak. Some companies use electronic leak detectors, geophones, and scuba gear to look for leaks. Once the leak has been found they are usually easy to repair.

How To Repair A Simple Hole In A Liner sells a simple adhesive patch kits for patching a vinyl liner. When properly applied, the patch should last as long as the entire liner. Here is the procedure for applying the patch.

It is always better to apply the patch behind the liner if possible. If the hole is above the water level, take a small amount of clear PVC pipe cleaner and clean the area to be patched. Be careful not to rub the pattern off the liner outside the patch area. If the hole is below water level, clean the area with an approved vinyl cleaner but be sure to remove cleaner residue.

Cut the patch material into a round or oval shape about 3 times larger than the hole. Most patch kits contain clear or solid color vinyl patch material. It is advisable to save some of the original liner material, either from the step or skimmer cutout, for just this occasion.

Apply the patch adhesive to the back of the patch. Spread evenly to the edges being careful not to spread so thick that it will flow outside the patch area when pressure is applied. Allow the adhesive to tack according to the instructions.

If the hole is above the water level, place the patch over the hole, smooth any wrinkles, and apply pressure evenly for 3-4 minutes.

If the hole is below water level, fold the patch in half so the adhesive side is lightly folded together. This is done to keep excess adhesive from possibly floating off the patch which could remove the pattern at the water line. Take the patch to the hole, unfold, and place on the hole. Smooth to spread out wrinkles and apply pressure for several minutes by standing on or placing a flat weighted object on the patch.

Dye test the patch as described in the find a leak section to make certain the repair is successful.

Larger tears in the corner can be repaired using the same method as above. In those situations it is better to take pressure off the liner in the corner by lowering the water level about 12” and then remove the liner bead from the track before patching. After patching, leave the liner out of the track for 6-8 hours before replacing the bead in the track and refilling.