Testing and balancing your pool water chemistry can sometimes seem overwhelming. With so many different chemicals and steps, there is a lot of information to manage. That’s why we put together this helpful guide for pool opening chemicals!
Testing Your Pool Water
Test Kit Type: It doesn’t matter if you use test strips or test kits, but it should be a 5-way test kit, so you can check chlorine, pH, Total Alkalinity, Calcium Hardness, and stabilizer. Smaller kits won’t check all five levels, and you’ll never achieve true water balance.
Shelf Life: Always test your pool water with fresh test strips or test kit. The strips usually have a date code on the bottom of the bottle, and generally last about 3 years from the manufacturing date. Test kit reagents should be replaced if frozen during winter, exposed to sunlight, or older than two seasons.
Accuracy: Test your pool water with precision, to get the most accurate reading you can. If unsure of the reading, read instructions and test again. Other ways to improve accuracy include clean testing vials, holding reagent bottles vertical while adding drops, and taking water samples from a depth of 12″, to avoid testing surface water.
Test Log: A small testing log, kept in a tiny note pad, can be surprisingly useful and enlightening, and prevents forgetting the adjustments made in prior days. Write down the readings, and amounts added. You can also use a pool testing app on your tablet or smartphone, for test history and treatment guides.
Balancing Pool Water
After testing your pool water, it’s time to balance the pool opening chemicals. Proper water chemistry balance is key to ensuring healthy, clean water. And getting the chemicals balanced at the start will save you a big headache down the road.
| pH | Total Alkalinity | Calcium Hardness | Stabilizer | Sanitizer |
|---|---|---|---|---|
 |  |  |  |  |
pH
Your pool water pH level is one of the most important components of water balance. Proper pH doubles your chlorine potency, is more comfortable for swimmers, and reduces the chance of algae and stains forming. When balancing pool opening chemicals, and whenever you shock the pool, adjust the pH to the low side; in the range of 7.2–7.4, otherwise aim for a normal pH of 7.5. When pH creeps above 7.6, add an acid to lower the pH level, and when pH is lower than 7.2, add a base to increase the pH level.
Total Alkalinity
The Total Alkalinity (TA) level of your pool water helps keep your pH stable and resistant to change, acting as a pH buffer. When TA is below 80 parts per million (ppm), the pH can fluctuate wildly, or become erratic and become hard to stabilize. Raise pool TA levels with Alkalinity Increaser. Conversely, if your TA reading is above 120 ppm, it becomes hard to adjust pH, locking in your pH at an incorrect high or low level. Lower pool TA levels using our safe Instant Liquid Acid, or granular pH Reducer.
Calcium Hardness
If your water doesn’t have enough Calcium Hardness, it can become aggressive and pull it out of pool plaster or tile grout. Soft water, with low Calcium Hardness, also tends to become foamy and cloudy, and can harm soft and shiny surfaces, like pool liners. Add a dose of Calcium Increaser to raise the hardness level to 200 ppm. If your Calcium Hardness level is too high, over 400 ppm, you can lower the hardness level (soften the water) by dilution (adding softer water).
Stabilizer
Stabilizer, also called conditioner, is one of the most important pool opening chemicals. A stabilizer chemical uses Cyanuric Acid to protect the chlorine from the sun. It doesn’t have much to do with water balance, but not having at least 30 ppm in the water will let the summer sun burn off your chlorine faster than you can add it to the pool! Add stabilizer as needed, to keep a 30–50 ppm level. If your level creeps up in the 50–100 ppm range, the solution is dilution — you can lower cyanuric acid levels by draining and refilling a portion of the pool.
Sanitizer
From the moment you open the pool, until you close it back down, you need to keep a constant level of chlorine in the pool. The final component of water balance is your sanitizer, or chlorine level. After balancing the water, shock the pool with granular chlorine, and then allow the chlorine level to drop to 1.0–2.0 ppm. Then, maintain the ideal chlorine level of 2–4 ppm with 3″ chlorine tablets, placed in a floater or feeder.
Tips on Pool Water Clarity
If your pool is still cloudy, after weeks of running the pump 24/7 with perfect water balance, you may have a problem with your pool equipment. Run through the equipment checklist below to rule out any issues.
Equipment
- If your pool has no main drain, hook up a vac head/hose into the skimmer, to improve circulation and draw water from deeper parts of the pool.
- Check the pool pump, to be sure the strainer basket or impeller isn’t clogged with any little bits, and is pumping a full volume of water.
- Cloudy water can be a sign of a filter valve problem, with water bypassing the filter. DE filters can pass DE powder through torn grids or cracked manifolds. Cartridge filters can be damaged, and like filter sand, will wear out eventually.
- If your filter pressure is not rising, your filter may not trap dirt. Ensure the pressure gauge works, and use a filter cleaner to clear out the filter.
Chemistry
- If your pool still has a lovely green hue, you may need to shock again. Follow label instructions, but hit it hard, until the water turns blue.
- Flocculant can be used if you are able to vacuum to waste with a multiport valve. Follow the instructions, and pour in the pool floc. Shut off the pump, and in 12–24 hours, suspended particles sink to the bottom, and the water is crystal clear.
- Clarifiers are an excellent filter aid. They attract very small bits of debris into larger clusters that are big enough for the filter to remove.
- Keep the water balanced, check it daily with a reliable test kit or strip, and make adjustments as needed.
Other
- Keep your pool clean while trying to clear it. Vacuum, skim and brush as often as you can to keep springtime out of your pool.
- Direct the return eyeball fittings in the same direction, to make a circular water flow around the pool.
- Check that your skimmer weir is installed and working properly.
Wishing you an easy spring pool opening!
I purchased the In The Swim opening kit for my above ground 24′ pool. There are no instructions in the box on which chemicals to add first,second, etc. Where can I get instruction sheet?
Hi Mike, sorry about that! The instructions would be
1. Reassemble pool and start filter.
2. Test and balance pool pH, alkalinity, calcium hardness and cyanuric acid levels.
3. Add stain and scale chemical, and clarifier dose and circulate filter overnight.
4. After 18-24 hours of filtering, clean filter and recheck water balance levels.
5. Shock pool with pool shock (if pool is green, more shock may be needed).
6. Brush, skim and vacuum pool. Filter for 48 hours after shocking, cleaning filter as needed.
7. On day 3 or 4, or even later, add the algaecide according to label dosage.
we have an older model hayward EC-75 filter with 1.5 HP pump, inground 20 x 40 pool size.
We took a pool sample to pool store; recommended to put in 32 oz phosphate and 2 shock ok did, noticed problem with pool pressure goes up to 20 quickly and the DE is not collecting any algae on the tubes so when it’s backwashed only see the DE clumped, something isn’t right. Bump it and pressure back up to 20. So the DE finger tubes not collecting and the pressure is our concern. What can you suggest.
Thank you.
Hi Cindy, the phosphate remover treatment often gunks up DE filters a bit, especially Perflex with the unique tube design. I would open it up, by removing all the little screws, and pulling the entire ‘nest assembly’ out of the tank, and give it a good hosing. Then soak in a DE Filter Cleaner, mixed into 5 gallons of water, just set the nest into the bucket, let soak for a few hours. Rinse thoroughly, and reinstall, and recharge with a big load of DE, 7-8 lbs lbs for the EC75. Also, avoid using a polymer clarifiers with your filter, use natural chitin based.
I ordered the super opening kit…I need step by step instructions please
Hi Charlotte, good question, thanks!
Technical Specifications:
• Step 1. Begin filling the pool. Add both bottles of stain away following the directions for use on back of the bottles. This will help control minerals that are in the fill water, protecting your pool from staining and scale formation.
• Step 2. As the pool is filling, add clarifier following label directions.
• Step 3. Once the pool is full, start the filter and circulate the water, and allow the system to recirculate the water over night. This will allow complete mixing of the clarifier and stain away with the pool water.
• Step 4. Once the pool has recirculated overnight, shock treat the pool by using the pool shock. Shock treatment will help give the “polished” look you will enjoy. Always broadcast shock directly in the swimming pool. Brush any settled particles.
• Step 5. Add algaecide according to label directions for initial treatment.
I had the same problem! PRINTED insttructuons should be included in the kit! Not everyone has use of a computer and internet!
Hi there,
I just opened my brand new Intex 15×48 metal frame pool. I have filled with water and have skimmer and pump running. I have no idea on what order I need to add the chemicals and what chemicals I need exactly. Online there are so many different answer it is overwhelming. Would you be able to point me in the right direction? Best, Elora.
Hi Elora, let’s see if I can make this simple.
1. Place 3″ ‘Trichlor’ chlorine tablets, 1 or 2 at a time, in a floating chlorinator. Replace them when they dissolve, about a week. This is for your daily chlorination.
2. Superchlorinate the pool every 3-4 weeks, or sooner if algae is visible. Add 1 lb of granular chlorine shock or non-chlorine shock or 1 gal of bleach, following label. This is to kill everything that escapes daily chlorination, remove chlorine byproducts, restore water clarity and also kills algae.
3. Lower pH level if it rises above 7.8, measured by a test strip or test kit. Test your chlorine and pH levels every few days, or 2-3x per week. High pH of 8.0 renders half of your chlorine useless!
Those are the bare minimum items you need to worry about. You likely have a small filter, and may benefit from using a Clarifier, added in weekly doses, if you have trouble with cloudy water, and may also want to use a good Algaecide, also in weekly doses (follow label dosage info), if you have trouble this summer with algae blooms. One more tip – run that filter nearly non-stop. If you are too ‘conservative’ with the electricity, you could spend twice as much in chemicals…
Hi Dave,
I just opened my spa from a long cold winter with fresh water and chemicals. Is it safe to say that if all of the colors on my test strip are good or perfect, including bromine, that the water is safe for me and my family from any harmful bacteria that could have been lurking. How would I know or how might I test for that?
Thanks.
Hi thank you for such a good question! For spas and hot tubs, bacteria is more of a concern than with pools, due to the relationship between number of gallons and number of users or bathers. Healthy spa water definitely starts with good water balance (ph, alk, calcium), and a good bromine level (2-4 ppm), and a regular shock treatment, before and/or after each spa use normally – to kill anything that escapes the bromine (which can be overwhelmed when several people get into the spa). You can test the spa for bacteria, using Bacteria Test Strips, I see that we don’t sell them, but you can find online – if you want to be really sure. But for the average home spa, used 2-3x per week, by 2-3 people, there should be little concern, as long as chemistry, sanitation and filtration are optimal.
Thank you Dave. Your answer, and your blog, has helped me immensely. Officially tested and clean.