First test results

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06-14-2006 08:29 PM
poolbee

First test results

Pool builder finally came and added stabilizer. After running pump/filter 4 hours I did initial tests.
FC 3
CC 1
pH 7.2
Alk 110
Cal 170
Cya 48
salt 3,200

pool temp 80

Since the Cya was just added , I am believing that it will rise some in the next few days? I was told not to clean the filter for 3 days so all the CYA is mixed in.

And the pH is on the low side. Should I wait until the Cya is completely dissolved before making any adjustsment? Or should I make any at all?

Will the CC go to zero once the Cya is up to snuf?

I swam for the first time today and the water is quite salty. Will this diminish as the water level drops(splashing out) and we add more, or rain? I think I would prefer the salt closer to the 2500 level.

One other thing-was this an error on my part or is this supposed to happen? When testing the Cal, there was a precipitate the same color as the water, just darker, swirling around the test container.

Any advise on the numbers is greatly appreciated.
06-14-2006 09:38 PM
CarlD

Re: First test results

Quote:

FC 3
CC 1
pH 7.2
Alk 110
Cal 170
Cya 48
salt 3,200

OK, with your numbers you cannot use Tri-chlor pucks anymore without getting into high CYA low pH problems. (if you are using them). If not, not to worry.

Your CC is 1. This concerns me. I'm not an SWG expert but I do know that with a CYA of 50 (close enough) you should be keeping your regular FC closer to 5 or 6 ppm--and because your CC is 1, FC of 3 is clearly too low--the CYA fully dissolving in (if it hasn't already) will make the problem WORSE, not better.

Actually, I'd like to see you shock the pool up to 15ppm to clear out that CC. Use ordinary laundry bleach to do that.

pH of 7.2 is nothing to worry about. It's a tad low but I would NOT adjust it since it's still well within the safe range (above 6.9). SWGs are notorious for pushing pH up for you, so in a while you may need to add acid. Aerating the water is the ONLY way you should raise your pH at this time. But the pH is still perfectly safe for swimming.

Alkalinity is PERFECT! Don't mess with it.

I'm guessing you have a concrete pool. If it's vinyl, don't worrry about or add calcium--you don't need it and it's only a problem when you have too much (500ppm). However, if it's concrete/tile/plaster/gunite you need to raise it to the 200-400ppm range.

For your sake, I hope CYA is where it's going to be. If it goes higher, you'll have to set your chlorine levels higher.

Not sure about the salt--I suspect as you backwash and refill it will get less salty tasting.
06-15-2006 12:33 AM
waterbear

Re: First test results

Quote:

Originally Posted by poolbee

Pool builder finally came and added stabilizer. After running pump/filter 4 hours I did initial tests.
FC 3
CC 1
pH 7.2
Alk 110
Cal 170
Cya 48
salt 3,200

pool temp 80

Since the Cya was just added , I am believing that it will rise some in the next few days? I was told not to clean the filter for 3 days so all the CYA is mixed in.
A week is better.
And the pH is on the low side. Should I wait until the Cya is completely dissolved before making any adjustsment? Or should I make any at all?
I believe you have a SWG....the pH will go up on its own...dont touch it. You will be adding acid to keep it down soon enough. Try to keep it around where it is now
Will the CC go to zero once the Cya is up to snuf?
How many hours a day does the pump run? You might want to increase it a bit. this can help with CC when you have a SWG. You should find that running the CYA close to 80 ppm and the FC at about 3 ppm will keep the pool nicely with no CC. Remember that you are supershocking the pool water in the cell whenever it is genterating.
I swam for the first time today and the water is quite salty. Will this diminish as the water level drops(splashing out) and we add more, or rain? I think I would prefer the salt closer to the 2500 level.
Running a SWG at lower salt concentrations will shorten the cell life. Most manufacturers recommend about 3200 ppm, some even higher.
At bit higher than recommended is better than a bit lower in terms of cell life. I run mine at about 3300-3400 ppm and really don't taste the salt.
One other thing-was this an error on my part or is this supposed to happen? When testing the Cal, there was a precipitate the same color as the water, just darker, swirling around the test container.
This is normal. The first reagent in this test causes the magnesium in the water to precipitate out as magnesium hydroxide so you can get an accurate calcium hardness reading. The purple specks you are seing in the water is the magnesium hydroxide. The color of the water should be a definite blue. If it is still purple then you have not reached endpoint on this test. Keep adding drops and swirling until you get no more color change on adding a drop and don't count that last drop.
Any advise on the numbers is greatly appreciated.

If you have a plaster pool you should bump up the calcium a bit but if those numbers are from your own testing I suspect that you did not carry the test out to completion. Keep your salt where it is and don't let it go much lower. The CC should go away once the CYA is dissolved and the system stabilizes. You can either bump up your pump run time or increase the cell output a bit to get some more FC in the water but I would wait until all the CYA is dissoved since you might find that the FC goes up a bit on it's own then.
06-15-2006 12:44 AM
waterbear

Re: First test results

Quote:

Originally Posted by CarlD

Your CC is 1. This concerns me. I'm not an SWG expert but I do know that with a CYA of 50 (close enough) you should be keeping your regular FC closer to 5 or 6 ppm--and because your CC is 1, FC of 3 is clearly too low--the CYA fully dissolving in (if it hasn't already) will make the problem WORSE, not better.

Actually, I'd like to see you shock the pool up to 15ppm to clear out that CC. Use ordinary laundry bleach to do that.

Quote:

Originally Posted by CarlD

For your sake, I hope CYA is where it's going to be. If it goes higher, you'll have to set your chlorine levels higher.

The rules don't really seem apply the same way with a SWG. I have seen in my own pool and in my customers pools with SWGs when I test their water that pools with CYA close to 80 and FC around 3 don't have very much if any CC (usually under .2 ppm if there at all). I have noticed that when the CYA drops to around 50 the CC starts to show up. Don't know why, cant really explain it, but I have been seeing it and I have had several customers that actually had to turn the output on their cells down once the CYA got into the proper range and their CC disapperared without shocking. Once again I suspect it is because the way the chlorine is being introduced into the pool (the water in the cell being 'supershocked' when the cell is generating)
06-15-2006 08:50 AM
poolbee

Re: First test results

Thanks. I have a vinyl pool so calcium isn't a real problem for me. I have an AutoPilot Digital 220 swg. The AutoPilot rep had me on boost all day yesterday after he added the CYA. My pool is 21,000 gallons according to the rep. Also, AutoPilot recommends CYA of 60-80. Do you shock whenever there is CC present and do you base your amount of shock on the CC reading or only on the volumn of the pool?
06-15-2006 10:27 PM
waterbear

Re: First test results

Quote:

Originally Posted by poolbee

Thanks. I have a vinyl pool so calcium isn't a real problem for me. I have an AutoPilot Digital 220 swg. The AutoPilot rep had me on boost all day yesterday after he added the CYA.
Good idea since it takes about a week for the CYA to dissolve and your FC to start holding in the pool. Monitor your chlorine levels and turn down the output as the CYA dissovles. You will see the FC levels start to go high and stay there.
My pool is 21,000 gallons according to the rep. Also, AutoPilot recommends CYA of 60-80.
The majority of SWG manufacturers do.
Do you shock whenever there is CC present and do you base your amount of shock on the CC reading or only on the volumn of the pool?

If you have a CC over .5 ppm that does not go away in a day of normal run time for cell then shock with bleach. Saves wear and tear on the cell. For a CYA level of 60-80 ppm shock to FC of 20 ppm. This would be about 6 gallons and 1 quart of ultra bleach for your pool. You will probably never have to do this once everything is set up.