I learned very quick after 3 trips to the nearest pool store that they were clueless, tested my water three times and I was stressing why the FC kept going to 0.5 ppm. They blamed high phosphates, a bad SWG cell (brand new), and not once mentioned that my CYA level was 5 ppm all three times.
This is sometimes the hardest point we need to get across to new members.
While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing. Plus, the results of their "testing" is used to convince you that you need to buy things. Why do you think that testing is free?
See, they mentioned phosphates. Why? They can sell you something to fix that.
The pool store want's you to have "a shed filled with white bottles of pool chemicals that had mysterious names and purposes". Unfortunately the pool industry has evolved into sales by scare tactics, misdirection, misinformation and marketing hype. Go in to the store and tell them your Total Alkalinity (TA) is low and they are going to sell you baking soda in a fancy package at four times the cost of WalMart. Do they have a right to make a profit, yes - but lets be reasonable. Heck, even their definition of "low" can many times put you on a pH roller coaster that's hard to get off of. Is that lack of knowledge or a sales technique to sell you more chemicals to control your pH????
So, why do pool stores push these products? Several reasons.
- Money would be the first. Unless a pool store is in Florida, Arizona or other year round areas they must make their profit in a short swim season. So, they need to sell you as much as they can as quickly as they can. Additionally, chemical sales is their bread and butter. Profit on a bucket of tabs is much higher than on a gallon of liquid.
- Secondly, we are an immediate gratification society. We want a magic potion that will fix our problem right now. This is where the industry has tried to ad items like clarifiers, floculants and the like which in a perfect world help get the bad stuff out of the water quickly.
- Third in my book is training. Most pool store employees learn on the job or through seminars taught by chemical salesmen. So, bad information is handed down from employee to trainee and the chemical salesmen teach them to push high profit items. This is especially true in large chain stores where employees are paid commission and managers jobs are based on how much product flows out the door.
Pool store methods can work for a long time and many are oblivious to what is happening in their pool. If you are in an area where your pool is drained down a lot each winter and winter snow/rains fill an overflow the pool each spring you are starting with a blank canvas, chemically speaking.
Are there good pool stores out there, yes! But, most of them are in the "sun" states where a family can own a small store and operate it 12 months a year, give good service and make a profit.
In the rest of the country you mainly have a high school/college kid who has about an hour training testing your water and telling you what to buy to add to your water. I guess that's like going into a carpet store and asking if you need to buy new carpet.
What the pool industry does not understand is that the internet is changing the industry around them. My favorite story is about my pool light. When I bought the house with the pool along with high CYA my pool light was not working. I could get a new bulb from Amazon for $19, but heck I'm part of that immediate gratification society as much as the next guy. I went down to the local pool store and there was the same bulb, $39. I talked with the manager. I didn't want them to match the price, they have to keep the lights on - just be a little more reasonable. The manager gave me two choices, take it or leave it.
TFP didn't create the methods we use, but we have fine tuned them to make them as "Trouble Free" as possible.
I have to say .... I love my TF-100...... WITH magnetic speedstir. 
