High Ph, Low Alkalinity and flaky white things

[jdlw]

Hi, I'm new to this forum and a relatively new poolowner. Although I've been reading a lot, I still have some questions. I apologizefor the long post but I've been having some problems!

My pool was opened early Wed AM and the pool guys put some chlorine in. EarlyThurs AM I put some salt in as the low salt light was on. Early Thurs PM, I went to pool store to get the watertested (I need to order a test kit) and was given the following results:

FC 6.44
CC 0.51
pH 7.8
Hardness 166ppm (it doesn't specify if it is specifically CalciumHardness)
Alkalinity 56 ppm
CYA 21ppm
Phosphate 374ppb
Salt 3100 (although my SWG said 2600)

I already started to make adjustments recommended by pool store before I foundyou guys. I've added 30 lb salt, approx. 28oz magic acid, 5lb Alk-a-boost(They recommended 18 pounds, but I stopped after 5 pounds when I found you guysand haven’t added anything else yet). They also recommended CalciumChloride and CYA but I wanted to check with all of you who are so much moreknowledgable than me. I just went to pool store and had water retestedand here are the results:
FC 4.79
C 1.37
pH 7.9
Hardness 164ppm
Alkalinity 71ppm
CYA 20ppm
Phosphate 464ppb
Salt 3500
Total Dissolved Solids 4475

My questions:

-I see in Pool School "Water Balance for SWGs" that CYA should beadded first (after salt). Everything I have read says not to add CYAuntil other levels are at the proper levels. Why is it different for SWGpools? (unfortunately I have already added some chemicals)

-Pool store and other sources say alkalinity should be 80 at a minimum. TFP says SWG pools only need 60-80. Does the fact that I have a heaterchange the target? Pool store concerned that a reading of 60 would resultin the copper being dissolved from the heater and damage over time to the poolladder etc. If I could keep Alkalinity lower, it might help with some ofmy problems (see below)

-Pool store wants me to raise hardness to at least 200 - but if I'm readingthis website correctly, my pool is perfectly fine at 166ppm or are there otherfactors I should be considering?

-Should I add more Clorox to shock the pool since CC isn't zero (in fact it has risen) and since there arephospates in the pool? I was lucky that our water looked pretty good whenthe pool was opened (most of our neighbors had pea green pools because ourwinter was milder/warmer than usual), but I did notice a little yellowy crustaround the water line which I assume was the beginning of algae. I'vebrushed down the walls. If I should addClorox, do I do it AFTER I put in CYA? According to TFP pool school I need to bring that way up. Also, should I add more Magic Acid to bring pHdown after CYA and shocking pool? Or after CYA but before shock?

-Also I had some problems with my pool last year, there were white flakes inthe pool....for those still willing to read, here is the history:
At some point, I noticed white flakes in the pool, particularly on pool floorby the return. some flakes were quite large. I thought somethingmight be wrong with my equipment and had the pool company look at it when theywere here for another issue. They said it was scale because of high pH(prob around 8 at the time, but it hadn't been there long because I hadregularly been having water tested and making adjustments). I got the pHlower, but the flakes never went away. However, we were in a viciouscycle of having a high ph reading (7.9-8), and after lowering the pH having lowalkalinity ...then after making an adjustment to raise alkalinity (to approx.80ppm) pH would be high again. Then I'd lower pH and alkalinity wouldrequire an adjustment etc etc. My total hardness through this was in thelow 200s range.
Finally the pool guys tested for total dissolved solids (TDS) and they werevery high at over 4000 (compared to recommended levels of 0-2000ppm –apparently salt is part of this but notat a 1 to 1 ratio?). So then they said maybe it wasn't scale but the factthe pool was saturated and solids were dropping out. The computerrecommended 75% drain of the pool! Aside from the time and money - itwasn't practical although I did drain a foot and replace with rain water andtap water. At pool close last fall I drained another 1 1/2 feetwhich filled over time with rain water (much preferable to tap water since rainis ph of 6.6% compared to tap water which is 8-8.1% and I don't want tocontribute to the cycle of high pH and low Alkalinity and then add so manychemicals that TDS rises again) However I do see some evidence of whiteflakes again this year – just had TDS tested and it has NOT gone down despitethe cumulative 2 ½ feet of pool drain. I don't know if its remnants on our equipment from last year or if it is stilla problem. (I’m going to attempt to clean our SWG) Any thoughts or ideasabout this (and /or should my targeted levels be tweaked because of thisissue?) Should I avoid Boric Acidbecause of our high TDS (I didn’t drain anything near 75% of pool)

Thanks so so much!!!!

 

[RobbieH]

OK, here we go:

CYA is different for salt pools because higher CYA cuts down on how hard the SWG has to work. FC does not have to be as high in relation to CYA in a SWG pool because the water is sanitized as it hits the ultra-chlorinated area in the salt cell.

TA of 60 is not going to do anything to copper. Heck, all my lines are copper!

If you have signs of algae, you need to SLAM.
Pool School - SLAM - Shock Level And Maintain

Ignore TDS

You need a good test kit so you can take this over yourself. Plus, pool stores are notorious for doing tests wrong, and then even worse selling you stuff you don't need. I recommend the TF-100, you may need the XL since you have a larger pool and need to SLAM.

TFTestkits.net

I can't tell you where your CH needs to be because you didn't say if you were a vinyl or plaster pool. If vinyl, it is irrelevant. If plaster, you need to be around 350-450, so you need some calcium in there.

- - - Updated - - -

Oh, when pH is off, it can cause white flakes, due to calcium. I usually only see this when either pH is WAY off, or CH is way high and pH is off.

No reason to avoid boric acid, we have found that for most people borates eliminate "white stuff" (white flakes)

 

[jdlw]

Thanks,
and Oops, just amended my signature to indicate that I have a vinyl pool.

What should I do first? I've read a little about SLAM, but don't have the kit yet. Also, I need to find a few more hours to find out how to adjust the SLAM procedure for a SWG (different CYA levels...etc?)

How low can Alkalinity go? When I add more magic acid (haven't found plain muriatic acid locally yet), the Alkalinity may fall below 60 again. And to confirm, I should add CYA first before adjusting my pH and then in another day or so work on the pH? Or do I SLAM first?

Regarding the flakes, I am always fighting high pH, but it's never gone above 7.9 or 8 and since I did have my pH tested a couple times a week (at least) last season, It's not like it would have been sitting at high levels for long periods (assuming the test results were accurate of course). And assuming it was due to high pH, how soon after the pH was adjusted, should the flakes have gone away? I did have multiple tests where pH was in balance (though alkalinity was a bit low) and yet the white flakes never went away. I don't know if it takes weeks or a month for that to happen and of course at some point the pH would have popped up to 7.9 again.

Thanks!

 

[RobbieH]

You can SLAM where you are now. You don't need to adjust CYA, at least not by much. If you already own tablets or a "shock" product, you can use that for now since your goal is going to be 70-80 on CYA, but for now I would not go higher than 30-40 because SLAM is a lot easier with lower CYA. If you do use tablets, it will help bring pH down, but anything around 7.8 or lower is just fine.

You can raise TA with plain old baking soda. I would not go over 80.

High pH is the only downside (as far as I am concerned) to SWG, but I'll take weekly additions of muriatic acid over daily additions of bleach any day.

 

[jdlw]

I haven't SLAMed yet because I still need a test kit (just ordered)...I am adding chlorine though as FC is falling and CC is rising - triage until my kit arrives. I don't want to increase my SWG above 60% because I already have high pH problems.

Questionool school says to get pH down to 7.5 (or lower) prior to SLAMing. Does that apply to SWG pools also? If so, the amount of MA I would need to get it to that level would likely bring Alkalinity down to the 40s based on my past (limited) experience. Is that safe? - especially since SLAMing could take several days or more with alkalinity low that entire time.

For example, I did add MA while waiting for my test kit. Got h20 tested today and pH has actually INCREASED despite MA although Alkalinity did decrease so my struggles with the two are still there:

FC 2.88
CC 2.07
pH 8.1
Hardness 157ppm
Alkalinity 65ppm
CYA 21ppm

Nobody has gone in pool yet so no aeration there yet. no water features turned on. Is the rise in pH because of aeration over the SWG? I'm wondering if I should turn it off (or down) and manually maintain FC levels while trying to get pH low enough. And turn it back to regular levels after all is done and CYA is in?