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The 7 Most Important Steps To Pool Chemistry Maintenance.

Adding Muriatic acid

In this post, Im going to cover the 7 most important steps to pool chemistry maintenance.

We will be using the AquaChek 551236 7-Way 100 Count Pool Water Test Strips to reference this section. At this point I suggest reading my blog posted titled The 7 Most Important Chemical Test Points Needed To Ensure A Safe Pool Or Spa.

Please Note: Follow all manufactures safety recommendations. Pool chemicals can be very dangerous if not used properly. Please read all warning labels on bottles and packages, and when in doubt consult a Pool Professional, product manufacturer, or local supply store with any questions. It cannot be stressed enough that chemicals should never be mixed with one another or with other products. For instance mixing Tri Chlor and Calcium Hypochlorite (shock) into the same bucket could cause an explosion. Mixing chemicals can also produce poisonous gases. There is never a reason to mix any chemicals together. You can add things like Chlorine and acid into a pool at the same time, but you would never put them in the same vessel and then add them. Another good rule to keep in mind is only add chemicals to the pool water. Never add water or pool water to the chemical. Keep all Chemicals in cool, dry storage areas away from children, in their appropriate containers and add to a pool following the manufactures recommendations!!

Total Hardness

The amount of Calcium in your pool is crucial to both the pool surface and equipment. If your Calcium levels are too low, the plaster can get etched and delaminate (fall off). If it’s too high, it’s easier for the surface, tile and equipment to get hard to remove scale. Usually Calcium is brought to proper minimum levels during the new pool plaster start up process, and doesn’t need to be checked very often. If the Total hardness is too low, you can add in Calcium Chloride Prills. These are added around the pool perimeter and are brushed in as they dissolve. You can purchase this Online at Clorox Calcium Hardness increaser or your local pool supplier. If the Total Hardness is too high, your pool will either need to be partially or completely drained with fresh water added in. I usually prefer a full drain and refill if a pool’s water is 5 plus years old, or if its Cyanuric Acid level is above 100 ppm.

Total Chlorine/ Bromine

This measurement is the total amount of Combined Chlorine and Free Chlorine. Combined Chlorine is the unavailable disinfectant in the water because it’s already been combined with a waste product. These combined waste products are also known as Chloramines. To get the Combined Chlorine level, take the Total Chlorine and subtract the Free Chlorine reading. If the Combined exceeds or is equal to the Free Chlorine, you must Super Chlorinate of Shock the pool. If the Free Chlorine is above, add in the appropriate amount of chlorine to achieve adequate levels. Total Chlorine should read between 1 and 5 ppm.

Total Bromine does not have a Free test range. This reading is total and doesn’t need to be referenced with any other reading. It’s typically used in Spas. It has a low pH and will make the water Corrosive. Make sure to Raise the pH using Soda Ash to avoid this issue when using. You can purchase Bromine at Leisure Time 45425.

Free Chlorine

The amount of available sanitizer that can kill any present bacteria. Its range should be maintained between 1 and 3 ppm for a pool and between 3 and 5 ppm for a spa. It’s best to keep your Free Chlorine higher than your Total Chlorine.

Different types of Chlorine

LIquid Chlorine

Liquid Chlorine is the primary disinfectant that I use. It comes in 1 gallon Jugs and is approx. 10 to 15 % Chlorine and 1 pound of salt. It has a high pH which means muriatic acid will have to be added to the pool along with the Chlorine though not necessarily at the same time. (Please note, never mix chemicals outside of the pool. Whatever is added must be done into the pool separately.) To add, simply pour the Liquid Chlorine into the pool along the perimeter while the pool pump is running. On average I use about 1 gallon per week to maintain adequate levels, but certain pools and conditions such as gallonage, amount of use, temperature, debris etc. may call for more or less Chlorine. It has a short shelf life, and should be purchased one case at a time. It should also be kept out of the sun and in a well ventilated area.

Calcium Hypoclorite (Shock)

I don’t use this Chlorine too often, primarily because its base is Calcium and over time will raise the levels of Total Hardness. I use this product to Superchloronate or Shock a pool when needed. You can also sprinkle some on plaster stains and algae spots to remove them. Some stains can’t be removed with this method. It’s a good idea to keep some available as it’s fairly stable as long as it stays dry.


This chlorine is the strongest that I use. It comes in either granular, pellet, stick or tablet form. I use the granulated form to oxidize and remove large amounts of algae from pools. However it can only be used on white plaster because it’s such strong chlorine and will bleach colored plaster.

I use the tab form throughout the swimming season only. The tabs act as a backup during the hot weather to supplement the liquid chlorine I use, helping to maintain a strong Free Chlorine residual. The reason I stop using them once the weather gets cold is because they can’t dissolve rapidly in low temperatures. The other and more important reason is because they contain Cyanuric acid (conditioner), which stabilizes them.

As has been mentioned in other posts, I only add in the minimum amount of conditioner because it’s a known carcinogen and will wreak havoc on a pools surface in high amounts. A very common mistake with both pool owners and technicians alike is the choice to use too many tabs or only tabs.

Trichlor also has a very low pH, and without a proper balancing agent, will destroy the plaster and equipment over time since it makes the water acidic and corrosive, in addition to adding high amounts of unnecessary conditioner. I use 1- 2 tabs, every week or every other week. Some pools require as many as 4 per week but 1 or 2 is usually most sufficient.


The pH of your pool water represents how acidic or basic your water is. It’s very important long term that the pH is maintained in the middle between 7.2 to 7.8. Most pools will require the use of Muriatic Acid which will bring the pH down. Muriatic acid is fairly corrosive as it’s a diluted form of hydrochloric acid (the stuff you that can burn through flesh and bone. Don’t be too scared!! Since Muriatic Acid is diluted, it won’t melt your hand if you get some on you. You would probably feel a slight tingling/ burning sensation, and you should dip your hand in the pool or wash the affected area with water immediately to relieve this effect. Avoid breathing in the fumes when your using it, meaning don’t have your face right over the jug while you’re adding it to pool water.

Muriatic Acid comes in 1 gallon jugs similar to Liquid Chlorine. On average, I use about an 1/8th to a quarter gallon of Acid each week to keep my pH in the optimum range. Again, each pool is different as well as each chemical regiment used, and this will affect how much Acid is needed, as well as any other chemical additive for that matter. For this, I can’t emphasize how important it is to test, adjust, and maintain your pool each week.

When adding Acid, I go to a return jet (the holes that push water into the pool, and pour directly onto the stream, thus distributing the acid evenly throughout the pool. An alternative place to add acid is in the deep end of the pool. The reason for both of these methods is to ensure the acid has enough chance to dilute into the pool before it can touch any plaster surface in a concentrated form. Acid can stain and damage a pools surface; therefore you never want to add acid to a pool that’s not circulating, the pools shallow end, or directly along a pool wall.

Extend the jug 1– 2 ft. over the pool surface with the bottom of the bottle partially submerged. With the cap removed, gently start pouring acid in the pool as you’re moving your hand and jug backwards parallel to the pool wall to prevent the acid concentrating in one spot. When you’re done, put the cap back on, and dip the entire bottle into the pool. This will wash off any residual acid that may have spilled onto the bottle.

Acid will stain concrete and most other surfaces, so be very careful not to have bottles sitting with acid residue on them. Keep them clean, out of the sun if possible, and in well ventilated areas.

If your pools pH is too low, you can add liquid chlorine which will raise it slightly. However if it’s very low, you will need to add a product called Soda Ash.

Soda Ash, or Sodium Carbonate, will raise the pH of water. I don’t usually have to add Soda Ash, but I keep some with me just in case. If comes in a granulated powder and caution is needed when adding. When it hits water, it starts dissolving and turns hot. It usually dissolves quickly, but if it’s in clumps, it will take longer and start to discolor the plaster surface if allowed to sit. You definitely want to brush Soda ash in to prevent this from happening.

Total Alkalinity

Alkalinity should be maintained between 80 and 120 ppm. It usually maps pH but not always. If your Alkalinity is too low, you can raise it by adding Baking Soda available from. I don’t usually need to adjust this test feature, but if I need to raise it I start with approx. 3 scoops from a 1 pound Super Pro Scoop. I then will wait a week and test it again. I prefer this method because it keeps me from adding too much at once. High Alkalinity is more difficult to adjust. However, in some cases it is possible.

The only product I’ve used to successfully lower Total Alkalinity is United Chemical Easy Acid. In my opinion and experience, Easy acid is effective for slight adjustments. If your Alkalinity is beyond 180 ppm, that usually indicates there are other components in your pools water that are keeping it that high. Maybe other pool professionals have had luck with these large adjustments, and I would love to hear about them, but each time I’ve tried, I ended up with wasted easy acid and no results. Things like Total Dissolved Solids (TDS) have an effect on all aspects of pool chemistry. Often times draining a pool and starting over is the best option.

Cyanuric Acid (Conditioner or Stabilizer)

Cyanuric Acid is used to protect Chorine molecules from the harmful effects of the sun. Pools without adequate amounts of Conditioner can lose all of their Chlorine within 30 min during the the hot summer months. Therefore it’s vital to have the proper amounts. As was mentioned in the section covering Tri Chlor, you want just the right amount of Conditioner to protect the chlorine, but not much more. It’s a carcinogen and in large amounts has a diminishing return and will stain the plaster and equipment with a purplish coating that’s difficult to remove, as well as fostering algae.

Conditioner either comes in a powdered or granulated form. I prefer the powdered version because it dissolves faster. Please note that its best to add Conditioner after the pools filter, pump basket, and skimmer baskets have been cleaned. You can add Conditioner between filter cleans, but I like to do it immediately after because Conditioner tends to attach to your filter grids as it’s dissolving. I’ll explain why this is important.

Let’s say you added Conditioner and a couple days later, realized the Filter needed to be cleaned. There’s a good chance much of the Conditioner you added will get washed out as your cleaning your filter grids instead of dissolving into your pools water. That’s wasteful and a good way to have a low Conditioner reading even though you added the proper amount last week. I did this once while doing a new plaster start up and had to learn this lesson the hard way, realizing the error half way through cleaning the filter.

If your reading is below 30 ppm, you should definitely add Conditioner. To do this, turn on the pools circulation system and add approx. 3 pounds directly into the skimmer. Most of it will dissolve and get distributed into the pool, but some will clump and settle in the skimmer basket. Eventually, it too will dissolve in a day or two so don’t worry. Wait a maximum of one week to check again and add more in if necessary.

I usually keep my Conditioner levels right below 100ppm. Although this is on the high side of acceptable, it’s necessary for me in my service region. Often times, my pools with a lower conditioner reading have a lower Chlorine reading as a consequence, and I would rather have adequate sanitizer levels throughout the week.

To lower Conditioner, the best method is to simply drain the pool, either completely or partially. I usually perform a full drain because its recommended pools be drained every 5 to 7 years to remove TDS and other built up compounds that can’t be removed otherwise. I’ve heard of conditioner lowering chemical agents, but I have no experience with them, and don’t know if their effective at all.

This is my basic weekly chemical regiment that I use to maintain my pools. As always, I don’t use this routine on each and every pool. This is the average chemical load that I have to apply to each pool I service. Some pools use more, some less. It takes a few weeks to understand and basically predict what a pools chemical reading is going to say each time you test. If you test your water, adjust accordingly, and still can’t get the results you expected, don’t give up.

You may be using the stripes wrong, not running the pools pump long enough, needing to clean the filter, etc. There could be many reasons your pools not responding to the regiment you deploy. I’ve had, and continue to have pools with challenging and confusing chemistry issues. But this regiment is my base for getting the job done. This recipe is based on the average 20000 gallon pool, per week, during the swimming season.

Chlorine- 1 to 2 gallons of liquid chlorine.

3” Chlorine Tabs- 1 to 2 tabs in the tab floater or feeder.

Muriatic Acid- 1/8th to 1/4 gallon of acid.

That’s it!!! Those 3 chemicals are what I know I will have to use each week per pool. Again, sometimes more, sometimes less, and you will be able to know ahead of time, in most cases, how much or little chemical adjustment your pool will need during each maintenance schedule as you progress and learn through trial and time. I highly encourage you to research outside of this blog if you can’t find the answers you’re looking for. I’m not the “know all” of pools and their many nuances. I’m a Certified Pool Maintenance Technician with a few years under my belt and some success within this business I’ve created. There is always room to learn and adjust.

Thank you reading my post. I hope this helps you on your pool maintenance path. Please read my bio below this post and contact me if you have any questions or suggestions for writing topics you would like to see covered in the Aquablog.

Rhett Blackwell


Mr. Blackwell is  the owner of Aquadoc Pool & Spa Care, LLC.  A leading pool cleaning company in Lancaster, Ca.  He became a Los Angeles County Swimming Pool Maintenaince Technician in 2014.  To find out more about the author click here.  If you would like to contact him go here.

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