Pool Maintenance Mistakes
Don't Make These Common Swimming Pool Mistakes
From Kevin Woodhurst, for About.com
If you have your own swimming pool, you are one of the lucky ones. In Phoenix, some people use their swiming pools all year long. Swimming pool maintenance doesn't have to be difficult, but knowing how to properly maintain your pool will make it last longer and be a safer place for family fun.
12 Common Swimming Pool Maintenance Mistakes
- Not checking your pool's chemistry often enough. Check the pool's chemistry twice per week in the summer and once per week in the winter. By doing this you can make minor adjustments to your water chemistry instead of big adjustments that create a wild up and down graph of activity.
- Allowing pH to get above 8.0. At 8.5 chlorine is only 10% active. At 7.0 it is about 73% active. By just maintaining pH around 7.5 the chlorine is 50-60% active. Keeping the pH in check will allow you to use to the full potential the chlorine that is already in the pool.
- Not keeping alkalinity between 80-140 PPM. Low or high alkalinity can affect water balance and ultimately a sanitizer’s ability to perform.
- Not checking TDS (Total Dissolved Solids) or calcium hardness on a regular basis. Check TDS every 6 months and calcium hardness every month. These also affect water balance which is different from sanitation, although related.
- Not cleaning the cells in salt water systems (chlorine generators). Corroded or calcified cells will produce little chlorine.
- Backwashing sand or DE filters too often. If you do this, the filter can never reach its cleaning potential. If you backwash on a regular basis for no reason, you are wasting water. Most filters require backwashing when the pressure gauge rises 8-10 PSI from clean.
- Not cleaning the skimmer basket and/or hair and lint pot in the pool pump often enough. If these are full of debris you will get little flow resulting in poor circulation, potentially creating a big problem.
- Adding chemicals, especially liquid chlorine, during the day. Try to add chemicals in the evening after the sun has set. You will get more out of them.
- Not brushing the walls and tile down often enough. If your circulation system is suspect, and many are, brushing down the walls will help eliminate algae problems. Keeping your tile clean will save you money. Once the tile gets calcified it becomes like plaque and will take a specialist to get it off.
- Make sure that you keep the space between the bottom of the cantilever on the deck and the top of the tile in check. If this cracks, then put in some silicon. You do not want water migrating from the inside of the pool out under the decking.
- Not running pumps long enough. You should run your pump about 1 hour for every 10 degrees of temperature. This assumes you have a decent circulation system. It is ALL about the FLOW! Circulation IS the key to a low maintenance swimming pool.
Not replacing broken or ition of an acid (similar to pH). Experts recommend "pooling" the acid in a small area of low current for a greater effect on alkalinity. That is, adding an acid will lower both pH and alkalinity. Walking the acid around the pool in a highly distributed manner is said to have a greater effect lowering the pH than the alkalinity. Pooling the acid has the opposite effect. A very important component of water balance, alkalinity should be maintained in the 80-120ppm range for "gunite" and concrete pools and 125-170ppm for painted, vinyl, and fiberglass pools. Levels should be tested weekly.
Calcium HardnessWhen we speak of scale, we are talking about calcium carbonate which has come out of solution and deposited itself on surfaces. It is a combination of carbonate ions, a part of total alkalinity and calcium, and a part of the Calcium Hardness level. The test for Calcium Hardness is a measure of how "hard" or "soft" the water is testing. "Hard" water can have high levels of calcium and magnesium. If these levels are too high the water becomes saturated and will throw off excess particles out of solution which then seeks to deposit themselves on almost any surface inside the pool. This is calcium carbonate scale; a "white-ish," crystallized rough spot. If the levels are too low, the water is under-saturated. If under-saturated, the water will become aggressive as it attempts to obtain the calcium it needs. Such "soft-water" will actually corrode surfaces inside the pool which contain calcium and other minerals to maintain its hardness demand. If your Calcium Hardness levels are too high you can use TSP to lower the levels or a product called Hydroquest 100. It can also be accomplished by dilution (adding water to the pool which has a lower calcium hardness content). Levels which are too low require the addition of calcium chloride. Recommended range for calcium hardness is 200-400ppm. Calcium Hardness levels should be tested weekly.
The Saturation IndexAlso called the Langelier Index, this chemical equation or formula is used to diagnose the water balance in the pool. The formula is "SI = pH + TF + CF + AF - 12.1." To calculate the Saturation Index, test the water for pH, temperature, calcium hardness, and total alkalinity. Refer to a chart for assigned values for your temperature, hardness, and alkalinity readings then add these to your pH value. Subtract 12.1, which is the constant value assigned to Total Dissolved Solids and a resultant number will be produced. A result between -0.3 and +0.5 is said to indicate balanced water. Results outside of these parameters require adjustment to one or more chemical components to achieve balance. This formula is not guaranteed; however, some readings for pH, calcium, and alkalinity which, if taken individually would be considered to be well beyond recommendations, can combine within the formula to produce "balanced water." The SI can be used to pinpoint potential water balance problems.
Comments
I'd like to add that those customers that think it is okay not to open their pool for a year.
Customers are surprised they just can' t skip pool maintenance for a year. The cost of chemicals and time to get the water sparkling clean, vacuum and getting the walls clean of algae is an expense they did not think about. This seems to happen more when a home is inherited with a pool or real estate foreclose pool openings and closings.The owners are not at all savvy when it comes to what they need to do to for pool maintenance or
winterizing and closing an inground pool.
While some of these tips are good, some are not or are inaccurate.
The percentage of active chlorine (hypochlorous acid) at various pH that is quoted is with no Cyanuric Acid (CYA) in the water. CYA acts as a hypochlorous acid buffer (as shown in the graphs in this post. With 30 ppm CYA in the water, the active chlorine level only drops by 14% going from 7.5 to 8.0 (as opposed to 53% with no CYA) and drops 26% going from 7.5 to 8.5 (as opposed to 82% with no CYA). The main reason to keep the pH below 8.0 is to prevent metal staining if there are metal ions (i.e. copper or iron) in the water. Also, the pH of human tears is around 7.5 though the eye is fairly tolerant of pH changes (it's more sensitive to the osmotic pressure from low salt levels). A higher pH can also lead to calcium carbonate scaling unless the TA and CH are kept at lower levels.
The TA level that is ideal depends on the source of chlorine that is used and on the amount of aeration in the water. Sometimes, a TA lower than 80 ppm is needed for more pH stability if the pH tends to rise due to carbon dioxide outgassing (especially in SWG pools and in spas using hypochlorite sources of chlorine).
Calcium Hardness (CH) does not change quickly unless Cal-Hypo is used as a source of chlorine or unless there is significant water dilution.
Only people who don't know better (i.e. not "experts") believe that the way acid is added influences whether or not the pH or the TA drop. Read this paper that debunked the "acid column" or "slug" method of adding acid. No matter how you add acid to a pool, 25-1/2 fluid ounces of full-strength Muriatic Aci (31.45% Hydrochloric Acid) in 10,000 gallons will lower the Total Alkalinity (TA) by 10 ppm. The pH will also drop with the amount depending on the TA level (and on other pH buffers such as borates level and to some extent, the CYA level). Though the pH drop can vary somewhat depending on the amount of carbon dioxide outgassing, pouring acid in one place quickly is bad for pool surfaces. The way to lower the TA is through a combination of acid addition and aeration of the water at low pH as described in this post.
Though pump runtime is important, it is even more important to maintain the appropriate minimum FC/CYA ratio if one wants to prevent algae growth using chlorine alone.
Most of this info as well as other similar info is described in the Certified Pool Operator (CPO) -- What is not taught post and in the Pool School.