Frequent Questions Pool Tips

Water Testing

Keeping your pool water balanced is one major key in proper pool ownership, which is why we found it extremely important to offer our customers free water testing. There are a number of different factors and minerals that we look at when we test your pool water. Teaching you the best practices when it comes to pool ownership is something we love to do, so we’ve broken down what we look at in a water test to help you understand what it all means.

Total Alkalinity

This is the measure of alkaline material in your pool such as carbonates, bicarbonates and hydroxides. These are necessary for proper pool water balance.

Ideal range: 80 – 120 ppm. (parts per million)

Alkalinity is your pool water’s ability to resist change in your pH levels. It acts as a buffer so when anything is added to the pool that would otherwise affect pH levels, the changes are much more manageable. It helps to keep pH levels within the proper range and prevent severe changes to your pool water balance.

This is one of the first things that we look at when we get your water test results. We recommend correcting your total alkalinity before pH to ensure efficient and proper correction of your pH levels, and because it will make reaching and maintaining the proper pH levels easier.


This refers to the degree of acid or base activity in your pool water. This is incredibly important to monitor in order to keep your swimmers safe and healthy.

Ideal range: 7.2 – 7.8

As the pH scale shows, anything zero to seven is acidic, with zero being the greatest acid activity. When your pool water’s pH is below 7.2, it is considered to be corrosive. This is harmful to swimmers’ and can burn skin and eyes. It can etch away at plaster, plumbing, pool surfaces, and the metals in your pool equipment and severely shorten the life of your liner. Water that is acidic will consume larger amounts of chlorine as the chlorine is less effective in these conditions.

Anything above a 7 on the pH scale is considered basic or alkaline (not to be confused with alkalinity.) A too-high pH level will increase the chances of scale forming and your pool water becoming cloudy as calcium becomes less soluble and ends up just floating around your pool. Bacteria is more likely to thrive in basic water. Swimmers’ skin may feel somewhat slimy. Since a too-high pH can also affect the way chlorine sanitizes your water, this can expose swimmers to potentially harmful microorganisms.

Calcium Hardness

This is the level of calcium that has dissolved in your pool.  Calcium, or calcium carbonate, is a naturally occurring chemical compound.  Issues involving calcium are typically a result of a larger chemical imbalance in your pool water.

Ideal range:  200 – 400 ppm.

Too much calcium in your pool water can corrode fittings, leave rust stains, and create tiny leaks in your pool equipment.  Calcium is actually more soluble in cold water.  Calcium buildup and scaling is a common problem that we see often in pool heaters.

Too little calcium can lead to problems as well.  Calcium is necessary to balance your pool water.  If there isn’t enough, your water will naturally try to balance itself.  It will do this by pulling calcium from other places, like plaster, metal fittings and heat exchanges.  It can destroy fittings, cause leaks and leave stains.

(Free) Chlorine

Your free chlorine reading specifically tells you how much chlorine is available to sanitize your pool water.

Ideal range:  1 – 3 ppm.

Chlorine is the main chemical that sanitizes your pool water.  Even if you have a salt water pool, your pool water is still chlorinated – it’s just a different process.  (Bromine pools are a different category.) 

We check to make sure that your free chlorine is higher than your combined chlorine, or the chlorine that has already combined with the contaminants it’s attacking.  This ensures your pool water is being properly sanitized.  We keep it easier for pool owners by having them focus more on their free chlorine level to keep swimmers safe.


These are a chemical compound that contains Phosphorous, a naturally-occurring, non-metal element.  These enter your pool in many ways, including dead leaves, twigs, dirt, natural water, lawn fertilizer and pesticides, swimmers, adding water, and any phosphorous-based pool cleaners.

Ideal range: 0, or as far under 200 as possible.

High phosphate levels turn your pool water green and cloudy and make it extremely difficult to maintain proper chemistry.  Phosphates feed algae and mask your free chlorine and eat it up quickly.  Proper chlorine levels are necessary to keep your pool inhospitable to algae.  It can clog up your filter and hurt your pool liner.  It could also affect the health of swimmers.

Low calcium levels can lead to high amounts of phosphates in your pool, which is one reason why a low level of calcium is necessary for proper pool water balance.

The presence of phosphates makes pool maintenance more expensive and time consuming.  There are day-to-day tasks you can do to help prevent phosphate levels getting too high.  These include:

  • Preventing lawn fertilizer or pesticides from making contact with your pool area.
  • Skimming out debris with a skimming net to remove them from your pool.
  • Vacuuming dirt and debris from your pool walls and floor.
  • Checking your filter regularly and cleaning it when necessary.

Tips for collecting a water sample

Ideally, your pool should be running for at least an hour before collecting a sample.

Use a clean, empty water bottle or container that you can tightly seal for your sample.

Collect the sample from elbow-deep in the water, away from skimmers and return lines.

When you come in for a water test

We ask that you be aware of how many gallons your pool holds or at least the dimensions of your pool so we can figure out how large it may be.  This will help us get a better understanding of what is going on with your water and how to treat it.

We will remove the water that we need for your sample and run it through our SpinLab Water Test.  We’ll create you a profile within our testing system so we can keep track of your pool water chemistry over time.  It takes just a minute or two to run the test and get the results.

Once we have the results, we will identify where the water imbalances are.  We will ask you a few questions regarding the maintenance you’ve done, the chemicals you have recently added, and any other possible factors that could be disrupting your pool water balance.

With all of that information, we will recommend products and a course of action to help correct any water chemistry issues and to get your pool back to pristine swim conditions.  We will most likely recommend a simple test with testing strips to see how well your pool water takes to the action plan.  You’ll typically wait 24-48 hours after adding any products to your pool before following up with a test strip to give your pool water time to adjust for an accurate reading.

Not sure about the results you get from the test strip?  Feel free to bring another sample into the Credible Pools store for another free water test.

Frequent Questions Pool Tips

How to Clean Your Pool Cover

GLI ProMesh Safety Cover.

When Credible Pools opens your pool at the beginning of the season, we spray off dirt and debris off of your cover before we remove it. If you want to scrub it before leaving it to dry and storing it away, we have some tips to help you do that.

After we have finished removing your cover and opening your pool, we will leave your cover in the location of your choosing so you can clean it. We will have removed the big debris from the cover before removing it to ensure that everything you have been protecting your pool from over the winter doesn’t fall into your pool.

It is not entirely uncommon to see mold on your pool cover. A mesh pool cover allows air and water to pass through, so they do not collect a great deal of mold. (Which is why we love GLI ProMesh safety covers.)


To clean the cover, it is best that you lay it out as flat as possible in a clean section of your yard. To clean your cover, you could use a mild detergent diluted with water or a spray-on pool cover cleaner.

If your cover is full of dirt and grime, you will need to scrub it with a pool cover brush or something similar, like a push broom. Never use any type of metal brush on your cover.

Be sure to rinse your cover thoroughly and be sure that all of the detergent, soapy water or cover cleaner has been removed completely. You do not want these cleaning agents sitting in the fibers of your cover.


Once clean, it needs to dry. Your cover must dry completely before you can put it into storage. This will prevent any mold or mildew from growing on your cover as it is locked away over the Spring and Summer months.

Move your cover into the sun. Laying it flat in your driveway or hanging it over a clothesline are the two best ways to make sure the entire cover can drain and dry. Leaving your cover to dry on the grass will take much longer and may potentially harm your lawn and kill your grass. You want people to notice your pool, not the giant patch of dead grass in your yard.


To store your cover, it is best to fold it in half over and over again, or a “fan fold,” until it is small enough to fit inside the storage bag that came with it. You may need a second set of hands for this task.

We recommend a secondary storage step; one step further than just the bag, but this is optional. It’s a good thought to either hang the bagged cover up high or to put it in a large container and lid. A large Rubbermaid container or a large trash can with a lid will do. This is to make sure that no creatures find their way into your cover and burrow there over the next few months.

All of this will help keep your cover in good shape and is ready to go at the end of the pool season when it’s time to reinstall it. If cared for properly, we’ve seen pool covers last nearly 20 years.

Are you considering replacing your current cover? Now is a good time to put that plan into action. Ordering a new winter cover early in the season will get you ahead of the rush and ensure that you will be prepared when pool season comes to an end.

Frequent Questions Pool Tips

The Brands We Choose and Why We Choose Them.

We would never sell you anything that we wouldn’t trust selling to our families or putting in our own pool. With over 25 years of dealing with just about all of them in the industry, we have confidently narrowed it down to the absolute best brands out there. And that’s all we sell.

Hayward shares our views of making your pool experience simple, low maintenance and hassle free. They have been manufacturing cutting edge, technologically advanced pool equipment worldwide for over 80 years. The pumps, filters, lighting, controls and salt-chlorine generators that are included with our inground pool packages are all Hayward products.

Their slogan is “We Build Better,” and we can vouch for that. In our over 25 years of pool experience, we’ve seen firsthand how Hayward products operate at maximum efficiency, and outperform and outlast the competition.

Raypak has effectively expanded to meet constant and fast growing demand for more than 70 years. Their ability to adapt to whatever the market calls for has resulted in a worldwide, highly regarded reputation for this company.

They manufacture the absolute best heaters and heat pumps in the industry. Their products not only meet but exceed customer and regulatory requirements. They align with the ISO 9001, which is defined as the international standard that specifies requirements for a quality management system. This made them the first boiler manufacturer to achieve the highest registration level attainable, really setting them apart from everyone else.

Raypak’s goals of high quality, reliability and energy efficiency is thoroughly executed in every product they put out, and that’s why we trust them.

Maytronics/Dolphin explains it best themselves.

“Dolphin has a rich heritage of over 35 years cleaning the world’s swimming pools. This heritage is built on a legacy of innovative pool cleaning technologies. Today, we continue to build on those technologies and provide pool owners with products that are efficient and fit into everyday life. Our latest generation of cleaners are cloud connected, giving you the ability to clean your pool from anywhere, anytime. With Dolphin, you can relax knowing your pool will be clean and ready for fun when you are!”

That’s why we include a Dolphin robotic cleaner in our inground pool packages. We even have them in our own pools. They have created the best easy, efficient, low-maintenance way to keep your pool pristine with just a couple taps on your smartphone.

Pentair’s mission is to make the most of water – life’s most essential resource. They deliver smart, sustainable solutions to ensure people can do just that. Their work and expertise goes way beyond just the pool industry and includes giving people the best tasting tap water to industrial water management.

Their dedication to safe, clean, healthy water is why we trust their salt systems to sanitize your pool. We trust them for our customers and our own families. The water you swim in needs to be clean and safe, just as the water that you drink needs to be. Pentair salt systems help us make sure your pool water is as good as it can possibly be so you can thoroughly enjoy your pool.

GLI is a leader in pool products. We put only GLI vinyl liners in our pools and in our customers’ pools and we swear by GLI safety covers.

They have an impressive range of liners, which guarantees that there’s one to give your pool the look you’re going for – from the most vibrant blues to shimmery finishes to textured sandstone styles.

We’ve found their mesh safety covers to be the absolute best. We have witnessed them stand the test of time as we’ve put on and removed the same safety covers year after year. Their Liner Doctors Program makes it simple to ship your cover to them to have it repaired or replaced should you need to. Their 20-point inspection will keep it in tiptop shape.

pHin is a younger but innovative company. They’ve developed Smart Water Monitoring technology to help you easily keep track of your pool or spas pH and ORP levels. Their bluetooth-enabled device pairs with their app so you can monitor your water levels from your smart phone.

pHin Smart Water Monitor is simple to learn and understand and will send you notifications if anything about your water chemistry is off. It’s a revolutionary way to care for your pool.

pHin is also branch of Hayward. All the more reason they can be trusted.

In their 40+ years, Dimension One Spas has become the leading manufacturer of award-winning hot tubs. They became the world’s first and only hot tub manufacturer to receive the Silver Medal Shingo Prize for being such a world-class organization. They’ve also achieved the Spasearch Buyer Guide’s highest “Recommended” rating.

We were honored to become a dealer (the only Dimension One dealer in our area) and to work with such an innovative and unique company. Continuous improvement is one of their goals and we are so glad we now get to witness this in the years to come. We are entirely confident in this brand and trust that their products will meet and even exceed all of our customers’ needs.

Frequent Questions

DE vs Sand and Cartridge Pool Filters

Cartridges are for Video Games and went obsolete 20 years ago!
What filter should you get? Ask yourself these questions:
  • Would you like your water as clean as possible?
  • Would you like to not have to disassemble your filter?
  • Would you like the easiest way to clean your filter?

The answer to these questions is DE (Diatomaceous Earth) Pool Filters and why we recommend them. Honestly we cannot figure out why any other filters are installed other than for initial cost or to generate repeat purchasing of cartridges. In DE Pool Filters, The DE powder is mixed into the filter and coats a filter “grid”, which then collects particles when your pool water is run through the filter. This powder is much finer than sand or cartridge media. Therefore, a DE pool filter can filter out the smallest particles, down to 2-5 microns. Sand filters get somewhere between 20-100 microns and cartridges capture 10-15 microns. That means that DE filters provide up to 50X TIMES more filtration than sand and 7.5X TIMES more filtration than a cartridge. For us, the choice is simple.

  • DE (Diatomaceous Earth) filters 2-5 microns
  • Glass Media (in a Sand Filter) will filter 5-10 microns
  • Cartridges filter 10-15 microns
  • Sand filters about 20-100 microns

Maintaining a DE filter is just a simple backwash procedure outlined here. DE filter powder is also very inexpensive so they pay for themselves in a very short amount of time compared to cartridges. We carry Pro-Grid Filters from Hayward with a 3-year parts & labor warranty. You will see a water quality difference if you choose this type of filter and have had a cartridge or sand filter on your pool. The water will be clearer and some even describe it as being polished!

Glass Media in a Sand Filter

If you have a sand filter and do not want to replace your filter, Glass Filter Media is a great option. We still like DE better, but Glass will filter down to roughly 5-10 microns.

Sand media needs to be changed out every 3-5 years depending on the water and debris load that is going through the filter. Glass media lasts about 2-3 times as long as sand filter media.

When you do switch to a DE filter

Because a new DE filter will remove so much more debris from your water, you may need to strip and clean it in the first few weeks. It can clog and cause some high pressure in your system quickly when you first make the switch because it is doing it’s job removing all the things your other filter did not!

Every filter needs disassembled and stripped and cleaned eventually. Unlike a cartridge filter which you could be doing weekly, a DE filter should typically only need this once or twice each season. We also provide this service as well.

Frequent Questions Pool Liners

New Pool Liner Installation

When you get a new pool liner installed for your in-ground pool, you probably will have some questions. A new pool liner will immediately make an older pool look new, plus it is an opportunity to change the color. It can even feel like a brand new pool even though it is just new vinyl. Our pool liner manufacturer is GLI and you can check out their colors and options here.

Every pool liner is custom made and needs to be precisely measured. You can schedule a measurement by booking an appointment. Or just pay for a measurement and we will get in touch to schedule. The price of the measurement will be taken off the final price if you purchase it from Credible Pools. The same goes for pool safety covers. We are free-form liner specialists, and free-forms are the hardest to measure for both liners and pool covers. Free-forms are also more expensive than a typical square or rectangle shape.

Once your pool is measured and the liner is ordered, the process to actually manufacture it is usually less than a week. Installation will be scheduled once it is received. The pool is drained with a pump and the old vinyl is cut out. At this point, there may be additional problems discovered and more work that needs done to repair walls and the bottom of the pool. After that our liner experts will hang it and vacuum it and begin filling the pool with water from a truck to set it in place.

A Note about wrinkles and imperfections

We do the absolute best job we can measuring and installing, and we rarely get wrinkles. They can occur though, but often we are at the mercy of how the pool was installed originally. The thickness of the liner also contributes to the ability of it to stretch and conform, so a thicker liner (28 mil) can actually end up with more imperfections in the end (so we normally recommend 20 mil depending on the pool shape). It is also not uncommon as the new pool vinyl sets and conforms in the first season for it to occasionally pop out of the track along the top of the pool which may also be affected by the existing bead receiver. The age and condition of the pool plus shifting and settling that happens over the years can also cause things to not be ‘perfect’ and perfection simply cannot be guaranteed with a new liner.

Frequent Questions

Electric vs Gas Pool Heaters?

The following information and recommendations are based on over 25 years of experience in pool installation and maintenance in Western PA

Electric pool heaters (Heat Pumps) cost more than gas pool heaters, but they are generally more efficient and cheaper to operate. With proper maintenance, electric heat pumps typically last longer than gas pool heaters. Electric heat pumps are essentially an air conditioner in reverse. They are also larger in size and heat much slower than a gas heater. Electric heat pumps work efficiently as long as the outside temperature remains above the 45ºF–50ºF range. Recommendations are situation dependent based on service availability and a number of other factors. For certain customers, heat pumps are a great option to consider.
Pros: Lower operating costs, environmentally friendly, lasts longer
Cons: Requires warmer ambient temperatures, higher initial cost

Natural gas heaters are able to maintain a constant water temperature in any weather conditions and heat water much faster. We do not recommend propane. If you want to keep your pool warm when it is colder (below 55ºF), then gas is your best option. If you OVER-size a gas heater you can get your pool to temperature quickly and with decent efficiency. Again, dependent on a number of factors, we often recommend gas heaters to customers if an adequate gas supply line is available.
Pros: Heats pool quickly, lower initial cost
Cons: Higher operating costs, generally fails sooner