Fairbanks
Answer
I reckon you're asking about salt generators.
There are many out on the market and their popularity has grown over the last 10 years. About half of all new pools being installed these days are set up with a salt generator.
There's something you should know about these generators. Most people believe that this is a non chlorine system. It actually is chlorine based. The idea behind these generators is to change salt into chlorine. Chlorine is actually a form of salt that's a little more "energized" than normal table salt. It's that property that allows it to effectively sanitize a pool.
With a salt generated pool, the actual salinity of the water is quite low. So low that unless you have exceptional taste buds, you won't taste it. You won't float any differently either than in fresh water.
There are a number of advantages with going salt. First and foremost is the "feel" of the water. A salt generated pool is a lot easier on eyes and skin than a traditionally chlorinated pool. The water is "softer". Because the chlorine produced by the unit is in a low constant dose, there's no high amount of chlorine in there to bother a person but it's still high enough and produced almost constantly, to keep the pool looking good. Another reason to go salt is the cost savings over time. These units are expensive initially but save a lot of money in chemicals that you don't need to add anymore. No more shock unless you get into trouble, less acid and less TA adjustment chems are needed as well. Salt generated pools tend to stay pretty stable in the water chemistry department. More so than any other form of sanitizer system. These systems are also automatic. You basically just set them and forget them with just a once a week check of the LCD screen on the control panel to make sure there's no issues. Maintenance usually just consists of a once a year cell cleaning which doesn't take long and the home owner can do this themselves.
The one drawback they have is the need to check your stabilizer levels a little more often than you normally do with a normal chlorine pool. You aren't using pucks anymore ( they have stabilizer in them) and you'll have to compensate for that when required. You'll also have to keep an eye on your salinity and add salt if required. This will happen once or twice per year with a sand filtered pool ( you're backwashing), only once as a rule with a cartridge or DE filter.
I disagree with what the other poster has said regarding retrofitting an older pool with salt. You can do it no problem at all. The only thing that would hinder that is if the pool were on Bromine before switching to salt/chlorine. In this case you'd have to dump the water since Bromine isn't compatible. If you're on chlorine now, it's not an issue. The only other thing I can think of that may be an issue is the pool's electrical grounding. If the pool was built properly it will be properly electrically bonded and there is no issue. If the pool builder cut corners and didn't bond the structure, ladders etc then there might be a corrosion issue 10 years down the road. It's easy enough to fix before the installation of the salt unit.
I also disagree with the other poster in that you DON'T need to still add chlorine. If the unit was sized and installed properly, it will work just fine by itself with no need for any additional chlorine unless you have a hundred kids suddenly using the pool and weren't prepared for it. Preparation is a simple matter of turning a knob on the control unit to up the amount of sanitizer produced before the party. That's it.
As a former pool tech and I was given the choice on what to use for a sanitizer system, I'd go salt in a heart beat. Less hassle, less overall cost and more enjoyment of the pool. So the answer to your question is yes salt generated pools are healthier and you're going to be cleaning any type of sanitized pool out. They all get dirty.
I reckon you're asking about salt generators.
There are many out on the market and their popularity has grown over the last 10 years. About half of all new pools being installed these days are set up with a salt generator.
There's something you should know about these generators. Most people believe that this is a non chlorine system. It actually is chlorine based. The idea behind these generators is to change salt into chlorine. Chlorine is actually a form of salt that's a little more "energized" than normal table salt. It's that property that allows it to effectively sanitize a pool.
With a salt generated pool, the actual salinity of the water is quite low. So low that unless you have exceptional taste buds, you won't taste it. You won't float any differently either than in fresh water.
There are a number of advantages with going salt. First and foremost is the "feel" of the water. A salt generated pool is a lot easier on eyes and skin than a traditionally chlorinated pool. The water is "softer". Because the chlorine produced by the unit is in a low constant dose, there's no high amount of chlorine in there to bother a person but it's still high enough and produced almost constantly, to keep the pool looking good. Another reason to go salt is the cost savings over time. These units are expensive initially but save a lot of money in chemicals that you don't need to add anymore. No more shock unless you get into trouble, less acid and less TA adjustment chems are needed as well. Salt generated pools tend to stay pretty stable in the water chemistry department. More so than any other form of sanitizer system. These systems are also automatic. You basically just set them and forget them with just a once a week check of the LCD screen on the control panel to make sure there's no issues. Maintenance usually just consists of a once a year cell cleaning which doesn't take long and the home owner can do this themselves.
The one drawback they have is the need to check your stabilizer levels a little more often than you normally do with a normal chlorine pool. You aren't using pucks anymore ( they have stabilizer in them) and you'll have to compensate for that when required. You'll also have to keep an eye on your salinity and add salt if required. This will happen once or twice per year with a sand filtered pool ( you're backwashing), only once as a rule with a cartridge or DE filter.
I disagree with what the other poster has said regarding retrofitting an older pool with salt. You can do it no problem at all. The only thing that would hinder that is if the pool were on Bromine before switching to salt/chlorine. In this case you'd have to dump the water since Bromine isn't compatible. If you're on chlorine now, it's not an issue. The only other thing I can think of that may be an issue is the pool's electrical grounding. If the pool was built properly it will be properly electrically bonded and there is no issue. If the pool builder cut corners and didn't bond the structure, ladders etc then there might be a corrosion issue 10 years down the road. It's easy enough to fix before the installation of the salt unit.
I also disagree with the other poster in that you DON'T need to still add chlorine. If the unit was sized and installed properly, it will work just fine by itself with no need for any additional chlorine unless you have a hundred kids suddenly using the pool and weren't prepared for it. Preparation is a simple matter of turning a knob on the control unit to up the amount of sanitizer produced before the party. That's it.
As a former pool tech and I was given the choice on what to use for a sanitizer system, I'd go salt in a heart beat. Less hassle, less overall cost and more enjoyment of the pool. So the answer to your question is yes salt generated pools are healthier and you're going to be cleaning any type of sanitized pool out. They all get dirty.
Regression Problem- Confim my Anwers Please?
sabunabu
Please see the below and my answers-- please let me know if you disagree and also if you know the answers to the 2 questions I don't. Any help is greatly appreciated.
PoolVac, Inc. manufactures and sells a single product called the âSting Ray,â which is a patent-protected automatic cleaning device for swimming pools. PoolVacâs Sting Ray accounts for 65 percent of total industry sales of automatic pool cleaners. Its closest competitor, Howard Industries, has captured 18 percent of the market.
Using the last 26 months of its sales data, PoolVac wishes to estimate demand for its Sting Ray. Demand for Sting Rays is specified to be a linear function of its price (P), average income for households that have swimming pools in the U.S (MAVG) and the price of the competing pool cleaner sold by Howard Industries (PH). The general linear form of the demand function
Qd = a + b P + c MAVG + d PH.
The attached computer printout presents the regression output from 26 observations (monthly data) on the price charged for a Sting Ray (P), average income of households with pools (MAVG), and the price Howard industries charged for its pool cleaner (PH).
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The printout of part of regression output from Minitab for the empirical demand is below:
Regression Analysis: Q versus P, MAVG, PH
Predictor Coef SE Coef T P
Constant 2728.8 531.7 5.13 0.000
P -10.758 1.330 -8.09 0.000
MAVG 0.021420 0.009452 2.27 0.034
PH 3.166 1.344 2.36 0.028
S = 73.0546 R-Sq = 96.6% R-Sq(adj) = 96.2%
Analysis of Variance
Source DF SS MS F P
Regression 3 3379846 1126615 211.10 0.000
Residual Error 22 117414 5337
Total 25 3497260
Source DF Seq SS
P 1 3327368
MAVG 1 22878
PH 1 29600
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1. An estimated demand equation for PoolVac is:
Qd = 2728.8-10.758P+0.021420M+3.166Ph
2. Evaluate the statistical significance of the three estimated slope parameters using a significance level of .05 or 5 percent (you can either use p-values or do a t-test).Please, explain how you decided each parameter was statistically significant or not.
Since the P values of all 3 variables are within the 5% confidence interval, each variable should be considered as staristically significant in determining the demand of the pool vacuums.
3. What is the exact level of statistical significance for estimated slope parameters on price, average income of household and price of related good? Please, explain how you know.
We should look at the P value for each of the slope parameters and in doing so, we find that price is 100% significant, average income (Mavg) is 96.6% (100-.034) and price of competition (Ph) is 97.2% significant (100-.028).
4. Discuss the appropriateness and/or interpretations of the algebraic signs of the three slope parameters, based on your theoretical expectations. Interpret the numerical values of the three slope parameters in the context of this regression.
5. Now evaluate the overall fit of the estimated (sample) regression equation to the data.
a. What percentage of variability in Qd (linear) is explained by a model? Does it indicate a good overall fit? Please, explain.
b. Verify whether the overall regression equation is statistically significant, another words, verify the goodness of overall fit .What is the exact level of significance for the entire regression equation?
Looking at the F stat which is 211.1, we can say the overall regression equation is significant since the absolute value is large. Also, the P value is 0 so there is no chance that this regression equation doesnât explain the relationship between the given variables and quantity demanded.
Answer
All of your answers are good. To say that the F statistic has a large absolute value is a little vague; one would generally either consult an F table to the appropriate threshold value or just look at the P value in the computer output. On the other hand, it isn't wrong, and if your instructor taught it that way you should leave it in.
Regarding the questions you haven't answered, number 4 refers to the direction of the effects on your dependent variable that come with changes in the independent variables. You should look at your coefficients and consider what would happen if you changed the values in your variables. For example, if the price of the product goes up, demand for the product goes down because of the negative coefficient associated with the price variable. If this seems confusing, try plugging in some different values into the equation and calculating the result. The negative coefficient makes sense, because people are going to be less interested in buying something if its more expensive. The question is asking you to evaluate both the actual effects on demand and the expected effects for each of the variables.
Question 5a refers to the R-squared statistic (R-Sq), which is the percent of explained variability as mentioned in the question. Yours is quite high.
All of your answers are good. To say that the F statistic has a large absolute value is a little vague; one would generally either consult an F table to the appropriate threshold value or just look at the P value in the computer output. On the other hand, it isn't wrong, and if your instructor taught it that way you should leave it in.
Regarding the questions you haven't answered, number 4 refers to the direction of the effects on your dependent variable that come with changes in the independent variables. You should look at your coefficients and consider what would happen if you changed the values in your variables. For example, if the price of the product goes up, demand for the product goes down because of the negative coefficient associated with the price variable. If this seems confusing, try plugging in some different values into the equation and calculating the result. The negative coefficient makes sense, because people are going to be less interested in buying something if its more expensive. The question is asking you to evaluate both the actual effects on demand and the expected effects for each of the variables.
Question 5a refers to the R-squared statistic (R-Sq), which is the percent of explained variability as mentioned in the question. Yours is quite high.
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