Add salt, slooow to change?

[RASelkirk]

Hi All,

For the 15 years I've been on salt, when I added a bag of salt (one bag = 400 ppm), the reading would come up and stabilize in < one day. Now when I dump a bag, the reading takes several days to make a change and it's only a 100 or two. Any idea what would cause this?

Russ

 

[HermanTX]

I looked at your PM logs but they have not been updated for couple of years. What is the level of your salt? Are you using the Taylor K1766 salt kit to test your salt? That is more reliable then looking at the output from your salt cell or test strips. Also, brushing, circulation time, affects the time it takes for salt to be fully mixed.

 

[jklocke]

My pool is about the same size as yours, and one 40lb bag of salt usually raises my level by 200-250 within a day or so. PoolMath says it should increase the salt level by 266 in an 18,000-gallon pool.

How are you testing salt? With a K-1766 or using your Aquarite?

 

[RASelkirk]

I usually depend on the Aquarite to give me readings. I do have a test strip kit though. My pool has always taken 8 bags to go from 0 to 3200 (at least three x's because of repairs/gelcoat/repaints). The thing is ... nothing salt-wise has changed in 15 years until the last two bag drops which have taken an inordinately long time to show up. Trying to get a handle on this extended time frame...

Russ

 

[HermanTX]

I usually depend on the Aquarite to give me readings. I do have a test strip kit though. My pool has always taken 8 bags to go from 0 to 3200 (at least three x's because of repairs/gelcoat/repaints). The thing is ... nothing salt-wise has changed in 15 years until the last two bag drops which have taken an inordinately long time to show up. Trying to get a handle on this extended time frame...

Russ

How old is your SWCG? Could that salt sensor be failing? In general. SWCG sensors are known for not being very accurate however every mfg. is different. Some have a +/-500ppm tolerance. So maybe it is just your sensor going bad.
The best method to test an accurate Salt level is using the Taylor K1766 test kit. It may be worth purchasing that and comparing it to your SWCG sensor readings.
I know for my Jandy SWCG, it reads 3100 at times, then 3300, etc. It bounces around because a SWCG sensor reads that bit of flow at that given instant. Also, it uses conductivity or amps/volts across that sensor to calculate a salt measurement whereas the Taylor kit measures the actual salt content of that pool water sample. My only suggestion is to consider a bad sensor in your SWCG and/or do some comparatitive testing with a proper salt test kit.

 

[RASelkirk]

I just used my Taylor kit, not sure which one as the label fell off way back when. It's the 10ml of sample, one drop of chromate, number of drops of reagent x 2. I got 13, so my salt is 2600 which is close to the Aquarite panel. I'm on my second main board (~ 5 years?) and 3rd T15 cell which was replaced this past spring.

Not sure why my pool would take 8 instead of 10 bags, it's been that way since since switching over to salt around 2006. I use Morton water softener salt crystals, I used to pour it over the edge while walking around it, but can no longer do that. Just dump the whole bag in the deep end now and when the barracuda gets a snort, the panel used to go to "hi" but that's no longer the case. I dump salt now and nothing seems to change. Don't think there's anything Morton would be adding to dilute the salt content that's not more expensive than the salt itself but it sure seems my last haul of bags is weaker. I'm sure there's a logical explanation and since winter is here, I've got a few months to ponder on it...

Russ

 

[HermanTX]

Just dump the whole bag in the deep end now and when the barracuda gets a snort, the panel used to go to "hi" but that's no longer the case. I dump salt now and nothing seems to change.

I think this is part of the issue as compared to you dispersing the salt around the pool. It just takes longer to mix since it is all concentrated in 1 area. After you do the dump, then take your brush and try to disperse it. That make help increase the mixing quicker.

 

[RASelkirk]

Herman, that's got to be it, at least part of it. Still, the ppm's only come up around 100 per bag even after a week of circulation (still doing 12 hrs/d). We've got a big rain coming Monday where I may have to pump out some level. After that, I'll dump 2 bags, brush it in, and see where it goes...

Russ

 

[RASelkirk]

Pumped out the pool Wednesday to 1" below the skimmer and since it's leaf-drop time here, the barracuda is out. Pool salt has been at 2600 for several weeks. Added two 40# bags of salt, dumping one on each side. Almost instantaneously, the salt went to "hi". Thursday the Aquarite was showing 3300, on Friday, after settling out, it was 3200. Guess that's 300 ppm's per bag. All seems good, just need to break out the leaf rake for the next month or so...

Russ

 

[Newdude]

Poolmath is saying 265 ppm per 40lb bag in 18k gallons.

 

[RASelkirk]

Poolmath is saying 265 ppm per 40lb bag in 18k gallons.

Yup, been there done that. I've either dumped or refilled at least 4 x's due to maintenance and/or hurricanes over the years. So why is my pool, after 31 years, just now becoming "normal" on the salt level? For the first 30 years, one bag was always 400 ppm's, then for some reason adding a bag does nothing, and 2 weeks later after adding 2 bags, it's finally meeting accepted specifications. The older I get the less I know, and the more I hate things that make you go hmmmm...

Russ