Dangers of high salt

dayhiker · Mar 19, 2010

I have been bitten by the cold water hiding the salt content. We had a very wet fall and winter. My swg has been reading about 1600. The few times I've turned the pump on (for cold nights) I've run it at 0. Last weekend I decided it was time to bring the salt level up. The poolcalculator said 380 #'s. I bought 10 bags of 40# and put 8 in. I checked salt last night and it said 7600. The salt strips appeared to agree both times but I have a hard time reading them.

What is the downside of just letting nature slowly wash it out with spring rains? I imagine it would only get down to 5000 by summer though. If I'm going to pump out water I need to do it now before I bring my other chemical levels up.

Also, if I have to pump out water, how do I do this? I have a cartridge filter so I never backwash. I don't think I can use the pool pump. I imagine I need to rent a pump to get the water out.

JasonLion · Mar 19, 2010

Salt levels above 6,000 start to be noticeably more corrosive than lower salt levels, and many SWGs (though not by any means all) shutdown when the salt level is too high.

Most cartridge filter systems have a garden hose style spigot somewhere in the pump house that you can use to lower the water level. The pool pump will pump water out through that spigot as long as the water level is high enough to reach the skimmers and the pump is running. If you have that setup, it is well suited to the continuous dilution approach, adding water at the same time you are removing water. Continuous dilution is slightly slower and used somewhat more total water, but is often easier overall.

Strannik · Mar 19, 2010

and if they don't shut down and are not designed for this salt range the transformer can burn out

Pool Clown · Mar 19, 2010

No problem, as long as you don't want to run your Cl gen for the next couple of years. At 7600, it will take quite a bit of rain to dilute that amount. When your unit says low salt, i would (as a consumer) always get a second opinion (other than test strips) before adding salt. it's easier to bring a sample to the local pool store and have it checked than having to drain part the pool. Your local pool pro will probably have the ability to drain your pool down, for a charge or course, but it may be worth not having to buy a pump and hoses and store them and, well, you get the picture.

dayhiker · Mar 19, 2010

Thanks everyone.

I did get a 2nd opinion, my swg and test strips were both showing around 1600. The bags looked like a regular 40# so it's not likely I put 8*60 = 480# in. I put 8*40 = 320#. The bags didn't seem bigger or heavier than I'm used to. I still have the 2 bags I didn't put in, so I'll check those. The 1600 number sounded right. It was over 3000 at the end of summer and we've had about the wettest fall in memory, then the usual winter rain, so diluting down to 1600 didn't sound out of line at all. Even if it was actually 2000, that's only a little high. I guess I'll start draining it tonight.

This does suck. I needed to get the Citric acid in there so that I can get the solar cover on and start running the solar panels in the afternoon to start pulling the temp up. Oh well, this shouldn't delay me too bad.

Pool Clown · Mar 19, 2010

Pool Clown said:
When your unit says low salt, i would (as a consumer) always get a second opinion (other than test strips) before adding salt.

polyvue · Mar 19, 2010

How long did the pump run after adding salt but before you used the test strips to affirm the SWG's report of 7600 ppm? I'm not sure why but my SWG/controller sometimes takes a long time to adjust to added salt, and you gave yours a whole lot to think about! :-D

The SWG on my system will squawk incessantly about marginally "low salt", then after I add a couple of bags (80#) - the equivalent of 150 lbs in your pool - it reverses its opinion very quickly, throws a check system error and displays some ungodly high level of salt. There are times it has taken many hours to reset but in any event, the salt level it reports isn't quite right for one to several days. (All this to say, your 7000+ ppm may come down some, maybe even a lot, over the next few days-- so you may not want to drain too much water.)

Parting blow: The salt test strips may not be reliable at that high concentration. I don't say state this authoritatively but I went through a lot of frustration with test strips last summer and ended up with a salt kit I love (well, deeply admire). duraleigh sells it for a good price but there are other on-line sources for this product. Taylor K-1766 Sodium Chloride Kit. About $23

dayhiker · Mar 20, 2010

polyvue said:
How long did the pump run after adding salt but before you used the test strips to affirm the SWG's report of 7600 ppm? I'm not sure why but my SWG/controller sometimes takes a long time to adjust to added salt, and you gave yours a whole lot to think about! :-D

The SWG on my system will squawk incessantly about marginally "low salt", then after I add a couple of bags (80#) - the equivalent of 150 lbs in your pool - it reverses its opinion very quickly, throws a check system error and displays some ungodly high level of salt. There are times it has taken many hours to reset but in any event, the salt level it reports isn't quite right for one to several days. (All this to say, your 7000+ ppm may come down some, maybe even a lot, over the next few days-- so you may not want to drain too much water.)

Parting blow: The salt test strips may not be reliable at that high concentration. I don't say state this authoritatively but I went through a lot of frustration with test strips last summer and ended up with a salt kit I love (well, deeply admire). duraleigh sells it for a good price but there are other on-line sources for this product. Taylor K-1766 Sodium Chloride Kit. About $23

I checked in this morning to say a similiar conclusion, but you hit on something else I've noticed.

First off, I got home last night, turned on the pump, got the hoses ready, re-checked the concentration and it was 3300. I decided that since most of the salt was in the deep end, the main drain was pulling a very high concentration and that I didn't give it enough time to redistribute, thus the #.

You point out some things I've wondered about. I'll be a little low, throw a few bags in and seemingly instantly the reading is ball park correct. THat's always baffled me. It's not like it senses the volume difference, knows the salt that will be on the way and corrects, but the numbers always seem about right. I have noticed the sensor lag on the back end too like you mentioned. Just weird.

Thanks for everyone listening and offering help.

I vacuumed the pool this morning to get the fines up, I still ahve some leaves, put the citric acid in, and it looks great. I'm about to dump some sequestrant in and go to the Botanical Gardens in B'ham to enjoy this 77 degree, sunny day. Thank goodness for spring.