My First post - high salt?

[jonnymac]

Hello Everyone,

My pool: 15,500 gal, Colored Plaster, Attached Spa, Flagstone (although it's more like Sandstone - more on that maybe in a later post) Coping, Sand Filter (currently filled with Zeolite), Propane Heater (with an alloy heat exchanger to prevent corrosion - but metal still flakes from the HX - more on that maybe in a later post), SWCG, In-Floor Circulation Popups.

My chemicals (I'm a fan of BBB): Muriatic Acid - several times per week to lower pH (although I'm seriously contemplating the higher pH concept because I'm tired of fighting it so hard). Baking Soda - several times per week to raise the TA back up after the acid lowers it. Borax (as I understand it) for pH stabilization. Jack's Magic Purple following each refill/top off to sequester metals.

My fill water: Well water. But it goes through a sediment filter, carbon filter, softener, and finally a hose-end "PreFresh" brand fill filter before it reaches the pool.

My season: Year round. Covered roof, aluminum/screen enclosure. Plastic windows during the cold season.

My chemistry: I maintain all parameters in the standard bands (but like I said, I'm probably going to give the higher pH thing a try), with the exception of TDS. The TDS got away from me recently (5600 ppm) when I topped off without using the PreFresh fill filter, yes even with the other filtration and softening. Note: Salt was also high (manufacturer's band 2700 - 3400 ppm) at 3800 ppm - confirmed with digital Salt meter. So...

I'm currently in the process of partial drains and refills to lower TDS and Salt. It works great. TDS is 4600 ppm and Salt (was) 3300 ppm. Problem is...

After the last Baking Soda addition, Salt rose back up to 3500 ppm and TDS remained at 4600 ppm. Question...

Is it possible the Baking Soda (and/or the acid for that matter) caused the Salt to rise?

Thanks in advance,
jonnymac

[aylad]

Hello, and welcome to the forum!!

Baking soda and acid don't cause the salt to rise. I don't know why you're getting an increased salt reading--one of the SWCG folks should be by here shortly and can probably answer that one for you.

I just wanted to understand something...you say you are using acid to lower pH, then baking soda to raise alk, then using Borax, which raises pH--why don't you just use the acid to lower the pH to 7.6, and leave the alk alone, since the lower alk is better for stabilizing the pH in a SWCG pool? Otherwise, you are battling yourself with chemicals!!

[jonnymac]

Hi aylad,

Leaving the alk alone sounds good to me. Should I still maintain some kind of limit or just let it go where ever?

As for the borax, I don't use it to raise pH. I'm under the impression it helps maintain pH (minimizes pH bounce) once the pH is where you want it. So I only add it occasionally to maintain about 50 ppm borates. I'll get a current borate concentration next time I test it.

jonnymac

[PoolDoc]

Hi Jonny;

Janet (aylad) is right that baking soda doesn't increase your salt (chloride) levels, but . . .

The problem is, you may not be measuring salt! If you are going by the 'salt meter' built into your SWCG, or if you have a salt meter, those don't actually measure salt, they measure conductivity. And baking soda DOES increase your conductivity, as does any chemical which ionizes when it dissolves.

If you have 'difficult' fill water -- and it sounds like you do -- you may be adding water that's low in actual salt (chloride) but high in measured 'salt' (conductivity). I have no experience or knowledge about operating an SWCG under those conditions, so I can't really tell you what to do. I can guess, bu there may be others who know more.

[rpoldervaart]

Hi Jonnymac,

Are you saying that you already have 50ppm borax and are still battling quickly rising pH? Like you, I have to add acid all the time but was hoping that borax would stabilize it. I hear what you're saying about flagstone being sandstone. My rock is turning to dust. Moss rock on my waterfall is even worse...

Robert

[kelemvor]

You need to get some sodium chloride test strips, they're a good bit more reliable than the conductivity test that your SWCG does. http://www.amazon.com/AquaChek-Salt-.../dp/B002OLP1L6 These are the ones I use (except I bought mine from leslies for a few bucks more).

This way you can eliminate the concern of other substances poisoning your salt conductivity test results.

Don't count on salt readings from your pool store either, as it's likely they're using a conductivity based test. This is the only test that my pool store consistently gives me bad results on (I have them run a test whenever I go buy something, then compare everything to my own results).

[aylad]

As for the borax, I don't use it to raise pH. I'm under the impression it helps maintain pH (minimizes pH bounce) once the pH is where you want it. So I only add it occasionally to maintain about 50 ppm borates.

Once you get your borate level to 50 ppm, there have been some that report stabilization of pH (as well as lower chlorine consumption, in some cases) but keep in mind that the rest of us use Borax to raise pH, so when you're adding it to maintain your borates, you're going to have to compensate with a little acid to keep your pH from rising (which should also help keep your TA lower, as well).

Janet

[jonnymac]

PoolDoc, kelemvor, aylad,

Thanks for the good advice. I'll use the salt test strips for more accuracy.


rpoldervaart,

Yes, I try to keep borates about 50 ppm. It's relatively easy. Concentration almost never rises and the only occasions in which I add borax is during partial water replacements. And yes, it minimizes my pH bounce, but like aylad said, it also raises pH. I don't use it to raise pH simply because my pH never goes down. My pH bounce (only in the up direction in my case and not at a rate I would consider "quickly rising") due to the chemical action of my SWCG and due to my fill water being on the alkaline side, would be worse without borates. So, don't be afraid of a little borax. Approximately 50 ppm, as far as I know, shouldn't harm anything.

As for the dust rocks, well that's a different story. If you're interested, I will share what I've done in the past, results, etc.

Thanks again everyone,
jonnymac

[famousdavis]

How are you measuring your salt levels?

On my SWCG, I get different readings all the time. But over time, I take the lowest reading that pops up with consistency to be my "true" reading. Also, when I've taken water samples to the pool stores (samples taken at the same time and place from my pool), the pool stores give different readings for my salt level. So, I take their salt meter readings with... wait for it ... a grain of salt!

[rpoldervaart]

As for the dust rocks, well that's a different story. If you're interested, I will share what I've done in the past, results, etc.

Good to hear about the borates. I'll be adding that soon.

I'd be interested in your rocks story. If you post another thread, leave a link here in this thread so I'll see it.

Robert