Do I need a salt chlorinator AND a floater?

Water Chemistry
1

Do I need a salt chlorinator AND a chlorine floater?

My new pool uses the Pentair intellicenter control panel and salt chlorinator.  My previous pool guy wasn’t familiar with this equipment, so I found a new guy who is.

However, he said the water looked “cloudy” and wants to buy a bucket of chlorine tabs and a floater. I thought the whole point of a salt chlorinator was so we wouldn’t have to buy chlorine?

As background, we’re two weeks into startup so haven’t even turned on the chlorinator yet.  And the new guy didn’t test the water (it doesn’t look cloudy to me).  I know salt chlorinators need help sometimes but surprised he wants a whole bucket of chlorine tabs already.

Does the new guy’s approach make sense, or is he being too aggressive?  Any advice much appreciated.  Thanks!

Charles K

2

Hi Charles,

The new guy’s approach doesn’t make sense to me. If the salt generator is properly sized for the pool it should be able to provide sufficient chlorine for balanced water conditions and should only need “help” if the water has a lot of organics, like algae, in it.

Doesn’t make sense to me that he didn’t test the water. That’s the first thing that needs to be done.

If you haven’t turned the chlorinator on yet what have you been doing for chlorine for the past 2 weeks?

Why would he want to put chlorine tabs, which I’m assuming are Trichlor in the pool without knowing what the stabilizer (CYA) level is?
You should consider getting a good test kit and taking care of the pool chemicals yourself.

At the very least, if the new guy has a good test kit, have him take a complete set of readings :

Total Chlorine

Free or Combined Chlorine

Total Alkalinity

PH

Calcium Hardness

Stabilizer (CYA)

and post them here and we’ll take a look at them.

If the new guy takes a water sample to the local pool store to have them do the tests, find a new pool guy or get a good kit and test the water yourself.

3

Thanks for your thoughts.  The prior pool guy was using liquid chlorine.  He didn’t turn on the salt chlorintator because of our pool plaster.

Total chlorine: N/A (water stayed clear after drops)

Combined chlorine: Same (water stayed clear)

pH: 8.0

Alkalinity: 80

My simple test kit didn’t cover hardness or CYA.

What do those numbers tell you?  Thanks.

4

Thanks for the info.

How long before you can turn the SWG on?

Until then, you’re old pool guy was correct to use liquid chlorine.

The numbers you posted tell me that the PH level is at the acceptable maximum range. This may or may not be an issue. The Total Alkalinity level is good.

But these numbers are meaningless without the rest.

Your pool is plaster. Calcium Hardness is critical to plaster pools. If the calcium level is too high, it will cause scaling on the pool walls and the Salt Water Cells. If it’s too low, the water will leach calcium out of the plaster causing etching of the plaster.

CYA, or stabilizer, is critical to protect the chlorine in the water from the sunlight destroying it. And lack of stabilizer in the water would cause chlorine readings of 0. Stabilizer should be kept at higher levels in pools with a SWG.

I hope you can see that we can’t be of much help without a fullset of readings.

J

5

Salt chlorinators can be turned on 28 days into startup, for plaster pool.

Ok got a test from the local pool store.  In case it matters the pool guy normally comes on Tuesdays.

Free Chlorine 0.1

Total chlorine 0.22

alkalinity 110

pH 8.5

calcium 262

CYA 85

Any additional insights from those numbers?

6

Hi,

My initial insight is the difference between the ph and alkalinity numbers between your tests and the pool company’s  tests. That’s quite a difference. But don’t assume your tests are wrong. Most pool companies now use a digital analyzer instead of testing the water with liquid drop reagents. If that’s what the pool company used and the tests you did were with liquid drop reagents, I would trust your numbers.

Your ph number shows the ph in the acceptable maximum range. Their numbers show a high ph.

Your numbers show total alkalinity in the ideal range. Their numbers show an alkalinity level that is too high.

Their calcium hardness numbers show a bare minimum level of CH. This will need to be addressed before you turn the SWG on and brought to a minimum of 350 ppm.

The CYA level, if it is correct, is within the acceptable maximum range. So you need to keep an eye on that.

For the chlorine, their numbers show that the combined chlorine in the water is below .5 ppm. So if their numbers are correct you don’t have any organics in the pool that would require super chlorination or shocking.

But you do need to get chlorine in the pool before nasties start to grow.

For a pool with a SWG and 85 ppm of stabilizer the chlorine level should be maintained at a level of 4 - 6 ppm.

So I would have the pool guy add 5 ppm of chlorine to the pool tomorrow (Tuesday). And unless he’s gonna come back every day until you turn the SWG on, you will need to maintain that 5 ppm level on the days he isn’t there.

One last point of information that you may not be aware of: A SWG requires that pool chemicals are adjusted so the water is brought into balance before the generator is first turned on. There is a recommended order for doing this.

1. Adjust the salt level. Most SWG mfgrs recommended range is 3000 to 3200 ppm. But some mfgrs require a higher level so check the manual. It’s also a good idea to add an additional 200 - 400 ppm to the mfgrs suggested salt level because the salt level tends to drop over time.

**2.**Adjust the CYA to between 70 - 80 ppm. You’re already there, just hav the pool guy check the numbers (assuming he has a test kit that will do this)

**3.**Adjust the Total Alkalinity to 70 - 80 ppm. This is IMPORTANT! So have to pool guy verify the pool company’s  number with his kit and adjust as needed.

**4.**Adjust the PH to 7.2 to 7.8. This is also IMPORTANT!

**5.**Adjust the Calcium Hardness level to 350 ppm

After the SWG is turned on, adjust the SWG percentage or pump run time so the Free Chlorine level stays between 4 and 6 ppm.

J

7

Thanks J, appreciate your insights.  They are much appreciated.

CK

8

You’re welcome. But I forgot to mention one thing. Don’t use any tablets to chlorinate your pool. Most tablets are Trichlor. They contain 53% stabilizer by weight. So each tablet adds stabilizer to the water. And your water, if the pool store readings are correct, has all the stabilizer it can stand.

Good luck,

J

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