Anyone having trouble with Salt test?

[waterbear]

Pool store says my salt is at 3000ppm. The pool was brand new in Aug '06, closed in Oct '06 and opened last week. Less than 3 months of usage and the SWG has already been replaced once before and now it's not working again.

Makes you thing the problem is not with the SWG but maybe the plumbing or hook-up, right?

The only other problem could be that the salt level really is too low and the tests have been inaccurate. Maybe I'll test it again somewhere else to rule that out as a possible scenario. Any other suggestions would be appreciated.

Thanks.

I suspect that your SWG might not be hooked up properly or is malfunctioning. You can get pretty accurate salt readings from the Aquachek White salt test strips. I have checked them against chemical tests and 2 different meters (Goldline and LaMotte) numberous times and they have always been right on the money (well within 200 ppm, which is the accuracy of the Taylor test).

[Jeffski]

I agree, but it is the second unit in three months so it is doubtful that the unit is malfunctioning. More likely it is hooked up wrong.

It is plumbed in the line right after the heater with the flow arrow pointing away from the heater. Water comes into the drains/skimmer - through pump - through filter - through heater - through SWG - into pool, right?

One other interesting yet probably irrelevant point... the return line that runs to the diving board/waterfall is plumbed between the heater and SWG so that water never goes through the SWG, just straight into the pool. That line is turned off 99% of the time and the SWG readouts appear the same whether that line is on or off.

[waterbear]

I agree, but it is the second unit in three months so it is doubtful that the unit is malfunctioning. More likely it is hooked up wrong.
It is possible to have 2 defective units or an improperly installed unit. Also, the pool store might have a miscalibrated meter. I would suggest getting the Aquachek White salt test strips. They are pretty accurate. If your salt is more than about 400 ppm from what the strips say then I would suspect a problem with your unit (many SWGs will show a salt level that is as much as 400-600 ppm off from the actual salt reading because they use conductivity to estimate the salt level. Are you able to maintain an adequate FC level in your pool? How high is your CYA? Pentair recommends between 50-75 ppm and, IMHO, I would put it closer to the upper end of that range. Id the flow light on? Also, what is your pH? If it's continualy high (above 7.8) then that can interfere with chlorine production A SWG does not eliminate the need for proper water balance and maintenance, only from having to add chlorine to your pool manually.
It is plumbed in the line right after the heater with the flow arrow pointing away from the heater. Water comes into the drains/skimmer - through pump - through filter - through heater - through SWG - into pool, right?
Sounds right to me
One other interesting yet probably irrelevant point... the return line that runs to the diving board/waterfall is plumbed between the heater and SWG so that water never goes through the SWG, just straight into the pool. That line is turned off 99% of the time and the SWG readouts appear the same whether that line is on or off.
That should have no impact on clorine generation or the readouts on the unit.

All SWGs will shut down in a low salt condition because it will damage the cell. Your intellichlor unit will operate with salt levels up to 6000 ppm. If you are getting a low salt reading and your salt level is near the bottom end of the range (I believe the Intellichlor shuts down at 2400 ppm) then just bump up your salt. Running your salt level higher will actually help prolong cell life. If your water is balanced and your unit is producing chlorine it is working. If the low salt light is on then add salt and see if it fixed the problem. I would recommend running your salt level at around 3200-3500 ppm with a CYA of around 70 ppm. Try to keep your pH at 7.6 (if you bring it lower you will possibly need more acid to maintain the pH since it will rise faster).
If you post a full set of test results it would be very useful.

[Jeffski]

Thank you for that great response. You guys are so helpful.

Here are the stats from my water test:

FC 0.7 - I think this has been steadily dropping because the SWG isn't running.
TC 1.5
TA 181
CYA 70
PH 7.5
TDS 3100
Temp 84

Here in Michigan we lower the water level in the pool a couple feet in the winter. The snow fall and rain fills it back up by the time we open in the spring, but it makes sense that every spring I should have to add salt due to draining a couple feet off in the fall, right?

I will get those test strips for the salt and check back with you guys. Thanks again.

[waterbear]

Thank you for that great response. You guys are so helpful.

Here are the stats from my water test:

FC 0.7 - I think this has been steadily dropping because the SWG isn't running.
TC 1.5
TA 181
I would lower this to around 80-90 ppm (or even lower). Several people have reported much less acid usage and much better pH stability with a lower TA when using a SWG. Once you do this you should have good pH stability if you keep your pH at aroun 7.6.
CYA 70
PH 7.5
TDS 3100
TDS is going to be the sum of your salt level and anything else dissolved in the water. I would suspect that yoursalt level is too low and you need to add salt. I suspect that your actual salt level is below the low salt cut off point of your unit. This is probably from winterizing your pool. What kind of filter do you have. If it is a sand or DE filter you also lose salt and stabilizer each time you backwash so the levels do need to be checked on a regular basis to maintain them.
Temp 84
I noticed you did not include a calcium test. Even if you have a vinyl pool where calcium is not an issue it is a parameter that needs to be watched with a SWG because calcium can also come from your fill water and if it is high you can get scaling on the cell, especially if you don't keep close watch on your pH.
Here in Michigan we lower the water level in the pool a couple feet in the winter. The snow fall and rain fills it back up by the time we open in the spring, but it makes sense that every spring I should have to add salt due to draining a couple feet off in the fall, right?
Exactly!
I will get those test strips for the salt and check back with you guys. Thanks again.

I suspect that when you test your salt you will find it is low!

[Jeffski]

AquaCheck strips said my salt was about 2400. This would explain why the SWG is not working. Not sure why the pool store said 3000 but I will not be going back there.

I added 50 pounds of salt yesterday at about 5pm. By 8pm the salt was testing at about 3000.

As of 9am today the SWG is still off and showing salt level <2500. How long will it take the SWG to catch up and realize the salt level is high enough?

I do plan on adding 50 lbs more but would like to see the SWG kick on first.

[waterbear]

Have you powered the unit off and then on? Sometimes that works. Give it about 48 hours with the pump circulating and brush the pool thoroughly to mix the salt during this time. If the SWG still reads low you have a problem somewhere with either improper installation or a defective unit. Call the manufacturer for help.

Pool store reading might have been off for several reasons. First and most likely is operator error in the test if it is a chemical test (including if they used a strip). Second and just as likely, if they used a meter it has not been calibrated recently.

[nater]

Jeffski,
With a TC of 1.5 and FC of .7, I'd get some bleach in the water pronto while you sort out the SWC issues. You don't want a green mess on your hands. You can use bleach to get a shock level in your pool according to the best guess chart and your CYA level. Maintain that until your TC = FC, then go to the maintenance level for FC.

[Jeffski]

Builder is going to send someone out to look at the SWG. After 100lbs of salt the pool is testing consistently at 3300ppm. Unit still doing nothing.

FC down to almost zero. How many gallons of bleach should I add to shock it? If I do that this morning, how long before the kids can swim?

[Jeffski]

Update:

FC 0 - adding bleach today until SWG is fixed
CYA - 35
PH 7.5
TA 180
Salt 3300

Does it make sense that my CYA would drop like that? It was 70 two days ago (or at least that's what the pool store said). These results are from my drop test kit.