T Cell 15 bad?

[kelemvor]

I recently purchased a house with a 3 year old inground pool and a salt system. The control panel from the salt system had to be replaced (black burned cap, and I didn't want to risk just replacing that and damaging the extremely expensive cell). I replaced that and the system shows "check cell" flashing and low salt. The system shows 2200ppm and wants 3200. When I get my water tested at the pool store they pretty consistently get 3000ppm (last time it was down to 2800, though) and tell me I don't need more salt. I visually inspected the cell and I don't see any scale buildup, there was some debris in there that I cleaned out. Took the cell to the pool store and they tested it and said it was working fine.

I was thinking of adding salt to get the system to read 3200, but how do I calculate the proper amount of salt to add for 12,000 gal pool to increase 1000ppm?

I've had the cell on 100% and the pump running 8h a day and chlorine levels continue to drop; perhaps it's generating some, but not "enough".

The cell (in fact the whole pool) is only 3 years old and the place was vacant for 7 months so the cell has only been run for 2 seasons; I'm hoping to avoid replacing it. Any suggestions on where to proceed other than my theory about increasing the salt until the cell says it's happy at 3200?

latest water test:
TC: 2.5 ppm
FC: 2.5 ppm
CC: 0 ppm
pH: 7.8 (I added 1.5cups muriatic, and haven't retested yet)
AD: 1
TA: 110 ppm
CH: 400 ppm
Sta: 90 ppm
TDS: 4200 ppm
Salt: 2800 ppm

I read some other posts about testing the cell, and I might try the "drip" method, but the salt system is definitely a slave to the pump so I can't do the bucket method.

[mas985]

1000 ppm in 12000 gallons is 100 lbs of salt. But I would add half at a time to see how much it moves up just to make sure there isn't a non-linearity in the salt reading.

Did the pool store use test strips to measure salt? I have found those to read fairly high compared to a drop kit or the SWG.

The bottom line is that you have to make the SWG happy so go by what the SWG is indicating. A failing cell will tend to read a low salt level so keep an eye on the SWG reading and if it continues to drop, it might mean a failing cell. Also, you might try and clean the cell anyway just to make sure there isn't any scale.

[kelemvor]

I did the acid wash (and discovered a bunch of debris under the square grid inside the cell tube). Put it all back together and reset, and it seems to have eliminated the check cell lights. Thanks! Still reading low salt @2300ppm (yup,up 100ppm? I did add a cup or two of salt last night, but being that 100lbs is what I'd need, I can't see how that would have made any difference at all.

The pool store has a rather complicated looking array of beakers and tubes. One of them has a motor that spins a device on the bottom, and they drop a plastic "pill" in while adding chemicals. There's a few other beakers they use, along with a device that looks a bit like a scale with an electric meter on the bottom (I'm guessing this is the salt test by testing conductivity?)

The salt I bought is "Salinity Fine Grain Pool Salt W/Stain Inhibitor 40 Lb. Bag" so I think I'll put half of that in tonight and see where I end up tomorrow for a salt reading. I think I read too much salt can seriously damage things, is that correct?

I think I'm on the right track, anyway. Thanks for the help!

[BigTallGuy]

If you go to the hardware store, you can probably find a 40 Lb. bag of Morton Pool Salt. On the back of the bag, it will tell you that the 40 Lb bag will raise the the PPM of salt by 480 PPM in 10,000 gallons of water. I would add 40lbs, Give the salt a day or so to dissolve, and check your reading. I would add smaller amounts from a second bag if needed, say half at a time. Bring it up slowly. If you over fill with salt you'll be draining and refilling.

[mas985]

Sounds like they are doing a TDS test which can have a lot of error as well unless the probe is calibrated often. Personally, I wouldn't trust a pool store test of any kind.

[waterbear]

I did the acid wash (and discovered a bunch of debris under the square grid inside the cell tube). Put it all back together and reset, and it seems to have eliminated the check cell lights. Thanks! Still reading low salt @2300ppm (yup,up 100ppm? I did add a cup or two of salt last night, but being that 100lbs is what I'd need, I can't see how that would have made any difference at all.

The pool store has a rather complicated looking array of beakers and tubes.
Most likely either a Taylor or Bioguard water lab.

One of them has a motor that spins a device on the bottom, and they drop a plastic "pill" in while adding chemicals.
That is a magnetic stirrer and the "pill" is a bar magnet to mix the chemicals. they are actually very useful in water testing, particularly for the calcium hardness, total alkalinity, and salt titration (if testing salt chemcially).

There's a few other beakers they use, along with a device that looks a bit like a scale with an electric meter on the bottom (I'm guessing this is the salt test by testing conductivity?)
Sounds like a MyronL salt meter, TDS meter, or their combo salt/TDS unit. MyronL are among the best meters of this type and yes it does measure conductivity. However, they need to be kept calibrated with standard solutions and if this is not done the results are meaningless.
The salt I bought is "Salinity Fine Grain Pool Salt W/Stain Inhibitor 40 Lb. Bag" so I think I'll put half of that in tonight and see where I end up tomorrow for a salt reading. I think I read too much salt can seriously damage things, is that correct?

I think I'm on the right track, anyway. Thanks for the help!

I if your salt level is too hight your unit will not operate and give you a high salt error. My suggestion is to get a tube of AquaChek Salt test strips. They are actually pretty good, unlike most test strips. See if they test closer to what your readout is or what the store testing is. This should give you some extra confirmation as to whether your cell is going bad or the pool store meter is off calibration.
FWIW, when cells start dying they often read low on the salt. If you call goldline tech support hotline they will ask you for the amps and volts your cell is putting out and can tell you if it is failing over the phone in many cases. It's worth a shot.

My suggestion is to try and clean the cell again. You CH at 400, TA at 110 and pH of 7.8 is certainly conducive to scale formation in the cell and I suspect that the unit was not properly maintained, which can affect cell life. Then again, the control unit you replaced could also be defective. You might want to contact whoever did the repair for you.

Finally, instead on wasting money on special 'pool salt' just use solar salt for water softeners (usually in a blue bag). I am going to make a guess that you live in Florida and your Pool Store is a Pinch a Penny (no, I am not psychic--Salinity is one of their 'house brands'. I actually shop at Pinch a Penny from time to time myself.) I will also guess that the water lab is a Taylor since that is what most Pinch a Pennys use. However, the results are only as good as the person doing the testing and that is often a problem. You really need to get your own test kit. A Taylor -2006 is the one you want (NOT the K-2005). You might have to order it online since most places do not stock it but only carry the less expensive K-2005. The difference is the chlorine testing method. The chlorine test in the K-2006 is far superior and much easier to use than the one in the K-2005!

[kelemvor]

Yup, that's the pool store I use. I didn't name the name because I thought I read a rule against that on the TOS when I signed up. I'll pick up some of those test strips, but I already added about 20lb of salt. Even if the store's salt reading is accurate and mine is not, I don't expect 20lb will raise it above the max level the chlorinator says is OK.

As for the board replacement, I did it myself. I don't really know anything about pools, but I do have a degree in electronics. I'm confident I installed it correctly, but I suppose it's possible it could be defective.

I need to find some kind of wooden or plastic device to try and scrape the cell as the manual suggests, I just don't have anything non metallic that can get in there, so I've just been using a hose with a jet nozzle, and the acid dip for a few minutes. Also, a few inches of the cell didn't get dipped because the manual warns not to get the part where the cord connects into the acid wash.

How long should I expect it to take before I start seeing the reading increase some after adding salt? I do have the generator switched "off" but I assume having it plugged in will allow it to refresh the reading?

[waterbear]

Yup, that's the pool store I use. I didn't name the name because I thought I read a rule against that on the TOS when I signed up.

Ben and mods, correct me if I am wrong but I do believe that it is ok to mention a store if you are not trying to promote the business but merely saying where you got a product. Even mentioning products can be against the TOS if they are mentioned to promote them but if you are listing the things you put into your pool (which is often necessary to get help with a problem) and not saying "Product X is a miracle that cleared my pool, saved my marriage, cured my dogs cancer, and brought about world peace" then I think you are OK.
Mod or Ben, please clarify if I am mistaken.
I know that many of the mods on here have mentioned Leslie's as a source for test kits (and also various online retalers).and Pinch a Penny is the Florida equivalent of a Leslie's store,which we don't seem to have. At least I have never seen one in S. Fl, N. Fl, on the Gulf coast, or on the east coast.

Also, a few inches of the cell didn't get dipped because the manual warns not to get the part where the cord connects into the acid wash.

The are talking about the connector that connects to the control box.
This webpage might help
http://www.goldlinecontrols.com/Support/Tips.aspx
If you want to spend the rediculous amount they charge for the 'cleaning stand' here are instructions for it's use
http://www.goldlinecontrols.com/Supp...ell_maint2.pdf
One of our regulars on here, Waste, who is a pool professional said that he uses and expansion plug to do the same. (the plugs used in winterizing if I am not mistaken.) I have never tried this and just use the bucket.
Do not dispose of the acid in the pool since this will just put the calcium back into the water. I neutralize the acid with some soda ash (doesn't take much) or baking soda (takes quite a bit and foams) and then flush it down the drain once the pH is fairly neutral..