Stick with vinegar for SWCG?

[davidwat]

I've been running salt water pool through winter with just pool service when I noticed a little green tinge to the water. Tested Chlorine <1. No notice from service but they added 1 bag salt. I added liquid chlorine and then SWCG boost with bubbles seen, but sometime in following week saw a Jandy General fault HIGH SALT, chlorine less than 1 and no bubbles in generator. Service added salt (maybe chlorine tabs?). Jandy says Salt 4400.
SWCG looks like this after 5 hours in vinegar (initially completely plugged).

This stuff is dense on top even after vinegar so that wooden probes did nothing. Metal picks able to expose 15-20% of channels so SWCG produces some chlorine. I will run chemistries and report, and I will admit to not paying attention over winter, but in the short term
1) should I just retry vinegar, maybe 10% if I can find it? If it softens up I will use wood to force deposits out.
2) Isn't reversing polarity supposed to take care of this?
Thanks,
David - Dallas

 

[kul]

Can you post your results from your TF100 test kit? Might give a clue on what is going on with your SWG and why that might have build up.

Your pool service sounds like they added salt when the pool might not have needed it. Not sure how often they come or if they test, but you may consider doing your own weekly tests as well so you can be more informed.

 

[davidwat]

Can you post your results from your TF100 test kit? Might give a clue on what is going on with your SWG and why that might have build up.

Your pool service sounds like they added salt when the pool might not have needed it. Not sure how often they come or if they test, but you may consider doing your own weekly tests as well so you can be more informed.

Current Chems
FC - 5.0 (after last night 1 gal chlorine and 10 hour 100% chlorine boost)
CC - 0.5
pH - 7.6 (It was 8.0 a couple of days ago. Currently with no acid added but 4 inch rain)
Tot Acid - 90
Ca Hardness - 350
Temp - 70 F
CSI - -0.17

(Addendum- salt after 2 bags is 3400)

Will increasing my acetic acid concentration a bit speed the process without putting plates at risk? Home depot carries 30% acetic acid.
Thx

 

[Flying Tivo]

That is way tooo much scaling. When was the last time you cleaned the cell? Vinegar will not do it or it will take to much time. Do not use any metal stick to clear the scale, use plastic or wood. You might harm the coating on the plates. After you remove most of the scale mechanically then use a hose with a jet stream like to remove the rest. After 90% of the scale gone then use vinegar to remove any remanent. Make sure to not leave it too much time or the plate coating will degrade.

 

[reggiehammond]

High TA and high pH will take your CSI positive very easily, leading to scale like this. Don't ask me how I know.
The need for CSI tracking is the only drawback about SWCG in Texas given our long swim seasons and generally high TA fill water.

Regarding getting them clean - do not use anything metal or you'll kill the cell completely. You likely have enough scale that you'll need a 10:1 MA solution and it might take several efforts. Set yourself a schedule to examine the cell quarterly - it's much easier to deal with scale earlier.

 

[davidwat]

That is way tooo much scaling. When was the last time you cleaned the cell? Vinegar will not do it or it will take to much time. Do not use any metal stick to clear the scale, use plastic or wood. You might harm the coating on the plates. After you remove most of the scale mechanically then use a hose with a jet stream like to remove the rest. After 90% of the scale gone then use vinegar to remove any remanent. Make sure to not leave it too much time or the plate coating will degrade.

"When was the last time you cleaned the cell". Never, but I installed it last May.

Current Chems
FC - 5.0 (after last night 1 gal chlorine and 10 hour 100% chlorine boost)
CC - 0.5
pH - 7.6 (It was 8.0 - Now after acid added? - can't reach pool service)
Tot Acid - 90
Ca Hardness - 350
Temp - 70 F
CSI - -0.17

Will increasing my acetic acid concentration a bit speed the process without putting plates at risk? Home depot carries 30% acetic acid.
Thx

The salt after the second bag was 3400 by TFT drop test.

 

[davidwat]

That is way tooo much scaling. When was the last time you cleaned the cell? Vinegar will not do it or it will take to much time. Do not use any metal stick to clear the scale, use plastic or wood. You might harm the coating on the plates. After you remove most of the scale mechanically then use a hose with a jet stream like to remove the rest. After 90% of the scale gone then use vinegar to remove any remanent. Make sure to not leave it too much time or the plate coating will degrade.

Thx. "Make sure to not leave it too much time" is that hours or days?

 

[Flying Tivo]

Thx. "Make sure to not leave it too much time" is that hours or days?

You need to babysit and when it stops bubbling you rinse with fresh water. You will also need to drain some water from you pool to bring down the salt level.

 

[Mdragger88]

They’ve all got you covered - just wanted to note that TA stands for total alkalinity not total acid as you put in post #3.
Alkaline is the opposite of acidic on the ph scale.

Managing pH and Total Alkalinity - Further Reading

www.troublefreepool.com

Hope this helps you have a little better understanding of what’s going on