St-Rite System 2

[KimC]

There are two ways to lower TA, Aeration (which also causes the pH to rise) and adding Muriatic acid (MA). With a salt cell, adding MA is better since cells cause the pH to rise anyway.

CYA comes in powdered and liquid. Powdered is less expensive. Liquid, when left to sit too long, needs to be shaken vigorously, like a can of paint that has been sitting.

I prefer the powdered. It dissolves slowly and can take about a week to show up in testing.

I add the powdered CYA by placing it in a sock, tying a simple knot to close it, and dropping the closed off sock in the skimmer basket.

It doesn't leave the water. Once its in, its in, just like salt or calcium hardness. Dilution is the only way to remove it in your area. AFAIK, there are no reverse osmosis services available

Regardless of what Pentair's manual says, don't add DE to a cartridge filter. The filter elements are the same as Jandy, Hayward, or Waterway. Its not good for the elements.

Here's the picture using photobucket's 4th option copy and pasted:

That looks like soda ash, a powdered pH increaser. Weird.

Scott

[KimC]

Good morning Scott,

You are a saint!

Any idea how much I should start out with? Do I just keep filing it up when the contents of the sock dissolve? I guess it will determine on how the pool tests??? I do add MA every week per the water sample but I will buy the powered CYA. So will they CYA take away the "soda ash"?

Have a wonderful day.

Kim

[waterbear]

There are two ways to lower TA, Aeration (which also causes the pH to rise) and adding Muriatic acid (MA). With a salt cell, adding MA is better since cells cause the pH to rise anyway.

Actually, adding acid lowers TA. Period. Aeration (causing carbon dioxide to outgas) raises pH without also raising TA again (like what would happen if you added a chemical to raise the pH). So to lower TA you add enough acid to drop the pH to around 7.0 (using a good test kit), aerate the water, and repeat the process until the TA is where you want it. This sticky explains the process. To lower TA you need to both add acid and then aerate (let CO2 outgass)!

I feel so uneducated right now....

You won't for long. It is actually pretty easy

FWIW, your too high TA and way too low CYA is what is contributing to your too high pH. Get the TA down to about 70 ppm and the CYA up to 80 ppm and your pH will not rise as fast and there will be less tendency to scale. We really need to know your Calcium Hardness history.

This statement is confusing to me. The water in AZ is very hard and I have drained my pool twice since it was built in 09. I am not sure how to get the TA down and the CYA up but would love to learn. The pool test companies tell me the water is too hard and suggest draining it but it is too hot right now. 110-114,degrees.Let me try and explain things. Just take it slow and re read each section a few times and it all should become clear!

You location is a key to what is going on. Parts of Arizona are known for very hard water and high calcium problems in pools. I would now say that what you are seeing is scale deposit. They key to minimizing it is to keep VERY CLOSE WATCH on your pH and not let it rise above 7.8 at any time (7.4 is better but it will require more frequent acid additions and almost daily pH testing). With a salt system it is imperative that you buy some CYA (stabilizer) and add enough to bring the level between 80ppm to 100 ppm (CYA as high as 100 ppm is often beneficial in Arizona with a salt pool) (assuming this is an outdoor pool) and then adjust the cell output to maintain your FC (free chlorine) at 5 ppm. This will do a few things:

1) the FC is going to be high enough so you should not have to worry about algae or cloudy water AND you will have no need to waste money on useless phosphate removers no matter how high the phosphates are!

2) the cell output is going to be MUCH LESS than it is with 20 ppm CYA which means the cell will be generating for less time which means it will create less hydorgen gas bubbles which means that there will be less aeration of the water which means there will be less outgassing of CO2 from aeration which means slower pH rise (catching breath now!)

Next, follow the procedure on lowering TA to get yours down to 60 or 70 ppm. This will do a few things:

1) Since you have very high calcium hardness (we really need test results on this to know exactly where chemicals levels are since scale deposits can ruin the surface of your pool if you let them occur!) lowering the TA will help your water be less likely to be scaling since water water will be more balanced (This means the calcium saturation index will be closer to 0 and yours is most likely very positive but without a full set of test results it cannot be calculated.)

2) It will also slow the speed at which your pH rises from outgassing of CO2, which is the main cause of pH rise in salt pools. Think of TA as the carbonation in your pool (it is!) as the pool loses carbonation though outgassing (think of a bottle of soda sitting on the counter going flat) the pH rises because there is less CO2 dissolved in the water (CO2 in water is basically carbonic acid. Operative word here is acid. Less acid = higher pH. TA is actually a measure of the bicarbonate in the water. At pool pH some of this converts to carbonic acid. If there is less bicarbonate (TA) then less can convert to carbonic acid which means less CO2 can outgas which means slower pH rise!

Finally, maintain the pH below 7.8 at all times. When you add acid to lower pH try not to drop too low (try not to go below 7.4) because, as I explained above, the more bicarbonate converted into CO2, the faster the CO2 gasses and since the lower you put the pH you convert more bicarbonate into CO2 which means it will outgas faster which means pH will rise faster! (catching breath again!)

High pH is the NUMBER ONE factor that predicts scaling! Your pH of 8.0, along with your high calcium and TA is a sure recipe for scale to form. Keep the pH in line and you minimize this tendency. Get the CYA and TA at the recommended levels and it becomes MUCH EASIER to keep the pH in line!

I purchased a second cartridge and could pull off some of the chalky powder and lumps to test. What will that tell me?

IF it fizzes and bubbles (gives off CO2) it is calcium carbonate (scale). It is interesting that you said it was chalky. Chalk is calcium carbonate!IF it does not fizz then it is some other type of deposit.

Also, scale does not readily dissolve in plain water so hosing off your cart is not going to get it off. To clean the cart you will need:

1) A container big enough to submerge the cart such as a plastic trash can or a large plastic storage bin (such as the ones RubberMaid makes) that allow the cart to be completely submerged either on it's side or standing up.

2) automatic dishwashing powder (like Finish or Cascade or a generic)

3) Muriatic acid

First rinse off the cart with a garden hose as best as you can to remove as much of the stuff as you can (use a short, non adjustable, small bore brass nozzle on the hose, they are the best for cleaning carts and only abut $2-$3 at most hardware stores and places like home depot.

Next, put the cart in the container and add enough water to cover. Measure the water as you put it in (I use a two gallon bucket. It takes a bit of time but you only need to do this the first time you clean the cart). Mark the container on the outside with the water level and how many gallons it is when you have it filled to that line with the cart submerged so you don't forget for next time when you just have to put the cart in and fill it up to the line with water.)

For every 5 gallons of water in the container add one cup of automatic dishwasher detergent powder and let it soak at least one hour (overnight is better). Hose it off well once again. This removes any organics and grease from the cart and gets you ready to acid wash it to remove the scale. If you do not soak the cart before acid washing YOU WILL RUIN THE CART SINCE THE ACID WILL CAUSE THE ORGANICS TO HARDEN INTO A CEMENT LIKE SUBSTANCE THAT CANNOT BE REMOVED SO DO NOT SKIP THIS STEP!

Now you want to mix up a 20 to 1 dilution of muriatic acid in the container. It's not as hard as it seems. For every 5 gallons of water (which is 20 quarts) you would add one quart of muriatic acid to the water (so if your mark on the container was 20 gallons, for example, you would need to add 4 quarts (1 gallon) of muriatic acid to that. If there is not enough room then remove a gallon or two of water and then add the acid. It will be in the ballpark and that is fine.

I would suggest putting the cart in the contaner, filling it to the mark, taking the cart out, then adding the acid and then putting the cart back in so you are not pouring concentrated acid right on the cart. Leave the cart in the acid solution until all bubbling has stopped, usually about 15 minutes. Rinse off the cart with the hose again thoroughly and you are good to go. It's not as much work as it sounds and, considiering the price of replacement carts, is well worth doing. A properly cleaned cart should be good for about 5 years if you clean it when needed like this (normally once or twice a year but it really depends on how fast it scales up). This procedure should bring your cart back to an almost new condition.

Remember gloves and goggles when working with acid! If you get any of the concentrated acid on you jump in the pool!!Don't dump the acid cleaning mixture in the pool since it is now loaded with calcium . Add soda ash (pH increaser, Arm and Hammer Super Washing soda from the Laundry Aisle of the grocery or Walmart--exactly the same thing) to it or baking soda (exactly the same thing as Total Alkalinity increaser, btw) to neutralize the acidity and then dump it (your test kit is your friend here. You want the pH to be between 7.0 and 8.0 before you dump it since this is usually the pH of most tap water around the country. If you use baking soda just keep adding it until there is no more fizzing (however, it will take a LOT more baking soda than soda ash)

The problem is my home is not being rented and I know live over an hour away one way. I dont trust the pool services so I go and clean the filter/cartridge and salt cell once a month.

You are going to have to teach your tenants about testing and adjusting the pH of the pool on a regular basis (and not using strips to do that either) and montoring the free chlorine (strips are ok for this) to make sure it does not drop below 5 ppm. It is the only way you will solve the problem! Also, you will probably not need to clean the salt cell as often if you follow these instructions since you will be minimizing scaling conditions, (However, checking the cell monthly is still a good idea!

Thank you for your expertise and your patience.

Hope this is helpful.

[waterbear]

So will they CYA take away the "soda ash"?

No, it is just one step of getting your water balanced. Getting your water balanced will MINIMIZE the tendency for the scale to form. Keeping your pH in line is the key. Bringing up the CYA and then readjusting the cell output (it will be lower after adding the CYA since the chlorine will not 'burn off' in the sun as fast) are just part of the formula form keeping the pH in line.