Water Balance: Difference between revisions
no edit summary
Matt Parnell (talk | contribs) (→pH) |
Matt Parnell (talk | contribs) No edit summary |
||
| (14 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
The contents in the sections below are attributed to multiple sources. While it's intended to be as accurate as possible, Fairway Farms Swim Club makes no guarantees of its accuracy. The content is to be used for reference purposes only. | The contents in the sections below are attributed to multiple sources. While it's intended to be as accurate as possible, Fairway Farms Swim Club makes no guarantees of its accuracy. The content is to be used for reference purposes only. | ||
Chemical quantities are based on a rounded figure of 200,000 gallons for the pool capacity (203,950 on the original drawings, not including volume within piping). | |||
== Overview == | == Overview == | ||
| Line 14: | Line 16: | ||
!Increase | !Increase | ||
!Decrease | !Decrease | ||
|Calcium Hardness | |||
|150 to 400 ppm | |||
|Add Calcium Chloride | |||
|Dilute (add water) | |||
|- | |- | ||
| | |Chlorine (minimum)<br>without Cyanuric Acid | ||
| | |1.0 ppm (pH: 7.2 to 7.5)<br>2.0 ppm (pH: 7.6 to 8.0) | ||
|Add | |Add Chlorine | ||
| | |Dilute (add water) | ||
|- | |- | ||
| | |Chlorine (minimum)<br>with Cyanuric Acid | ||
|7.4 | |2.0 ppm (pH: 7.2 to 7.5)<br>4.0 ppm (pH: 7.6 to 8.0) | ||
|Add | |Add Chlorine | ||
| | |Dilute (add water) | ||
|- | |- | ||
| | |Cyanuric Acid (stabilizer) | ||
| | |Up to 40 ppm (per Chemtrol) | ||
|Add | |Add Stabilizer (Cyanuric Acid) | ||
|Dilute (add water) | |Dilute (add water) | ||
|} | |} | ||
=== Measurement and Adjustment Order === | |||
As important as it is to adjust these factors to maintain water balance, the sequence is the most important: | As important as it is to adjust these factors to maintain water balance, the sequence is the most important: | ||
| Line 41: | Line 49: | ||
== Total Alkalinity == | == Total Alkalinity == | ||
Total alkalinity is the measure of the water's ability to "buffer" from wide pH swings. A buffer is a chemical system that resists change when acids or bases are added to the water. In water with no buffer ability, pH can shift dramatically. | Total alkalinity is the measure of the water's ability to "buffer" from wide pH swings. A buffer is a chemical system that resists change when acids or bases are added to the water. In water with no buffer ability, pH can shift dramatically. This rapid fluctuation of pH is called pH bounce, and the result is a highly unbalanced water condition. | ||
{| class="wikitable" | |||
!Ideal Range | |||
|80 to 100 ppm | |||
|- | |||
!To Increase | |||
|<b>Add sodium bicarbonate (baking soda)</b><br>28 lbs for +10 ppm<br>50 lbs for +17.9 ppm<br>(10 ppm/1.4 lbs for 200,000 gallons) | |||
|- | |||
!To Decrease | |||
|Usually not necessary; will decrease with the addition of acid. | |||
|} | |||
Per PHTA, alkalinity should ideally be kept between 80 and 100 ppm when calcium hypochlorite is used as a sanitizer. Worst case, it must be no less than 60 and no greater than 180. More broadly speaking, a range from 80 to 120 is often cited as acceptable. The state and county do not appear to have a standard that supersedes this guideline. | |||
{| class="wikitable" | {| class="wikitable" | ||
| Line 64: | Line 85: | ||
The most common problem in the total alkalinity test is caused by a high level of chlorine. When excessive chlorine is present in the sample, one of the two reagents used in the total alkalinity indicator will bleach out. When this happens, the endpoint changes from blue to yellow instead of green to red. To avoid this problem, repeat the test with an extra drop of the first reagent, thiosulfate. This should destroy the excess chlorine and solve the problem. | The most common problem in the total alkalinity test is caused by a high level of chlorine. When excessive chlorine is present in the sample, one of the two reagents used in the total alkalinity indicator will bleach out. When this happens, the endpoint changes from blue to yellow instead of green to red. To avoid this problem, repeat the test with an extra drop of the first reagent, thiosulfate. This should destroy the excess chlorine and solve the problem. | ||
=== Adjustment === | |||
Pour bag(s) of sodium bicarbonate slowly into the surge tank. This should ideally be done late in the day to allow it to dissolve overnight. After pouring, the Chemtrol may briefly alarm due to the elevation of pH and TDS (conductivity) readings due to the spike in concentration within the filter system. The alarm should clear after several minutes. | |||
If possible, use the full bag to avoid keeping partial bags on-hand. | |||
Sodium bicarbonate can be purchased for about $40 from Aquatic Source in Brighton (plus delivery charge) or B&B Pools in Livonia. | |||
Re-test alkalinity after six hours. | |||
== pH == | == pH == | ||
[https://en.wikipedia.org/wiki/PH pH] is the "potential of Hydrogen"; a scale specifying the acidity or basicity of a solution, measured on a scale from 0 to 14: | [https://en.wikipedia.org/wiki/PH pH] is the "potential of Hydrogen"; a scale specifying the acidity or basicity of a solution, measured on a scale from 0 to 14: | ||
{| class="wikitable" | |||
!Ideal Range | |||
|7.4 to 7.6 | |||
|- | |||
!To Increase | |||
|Add Soda Ash<br>(usually not necessary) | |||
|- | |||
!To Decrease | |||
|Add Hydrochloric (Muriatic) Acid<br>(should be automatically dispensed) | |||
|} | |||
=== Testing === | |||
pH is a colorimetric measurement that uses a color indicator to identify pH ranges. Most tests use phenol red, with a test range of 6.8 to 8.4. When testing pH, it is important to carefully understand and follow the directions provided with test kit. | |||
=== False Readings === | |||
Sometimes, high levels of chlorine will quickly convert phenol red into a new indicator that is dark purple when the pH is above 6.6. A common mistake would be to confuse the purple color for dark red and wrongly add acid to the pool. | |||
=== Background === | |||
* A pH of 7 is neutral. | * A pH of 7 is neutral. | ||
| Line 81: | Line 133: | ||
The ideal range of pH is targeted to be 7.4 to 7.6. A common myth is that this is very close to the pH of the human eye, often cited as having a pH of 7.5. However, this [https://www.ncbi.nlm.nih.gov/pubmed/7469869 isn't quite the case]. | The ideal range of pH is targeted to be 7.4 to 7.6. A common myth is that this is very close to the pH of the human eye, often cited as having a pH of 7.5. However, this [https://www.ncbi.nlm.nih.gov/pubmed/7469869 isn't quite the case]. | ||
== Calcium Hardness == | == Calcium Hardness == | ||