Help with adjustments after testing with TF-Pro - fresh gunite build

[angelleye]

Gunite pool build finished a couple of months.

I've been using PoolMath with strips and comparing with the store tests, and of course having strange conflicts between my strips and what the store was giving me. They were also telling me to use "No Mor Problems" which according to most of you here seems to be a bad thing, so I've stopped doing that. Only did the initial and one week of follow up.

I went ahead and ordered the TF-Pro Salt test kit, which I recently received. I've also been looking at the PoolMath action steps, and I see it asks me what type of chemical I'll be using, and it lets me choose between liquid or dry in many cases.

I looked up what dry is, and saw that it apparently works very similarly, but is easier to handle and store than other chemicals. I wound up buying big buckets of "Cyanuric Acid - Chlorine Stabilizer" and "ph Reducer" from intheswim.com. No returns on these items.

After that I started seeing info in the forums about how the liquid acid is better (although I really don't like working with it), especially for salt pools which I have. Can I use this stuff I got until it's gone, or would it cause problems?

I've been fighting high pH using Muriatic Acid so far based on pool store recommendations. Yesterday afternoon my pH was showing 8.5 based on strips, so I dropped about 3/4 gal. of acid in. It also rained. Then in evening I checked with strips again and pH was showing around 6.8.

I received my TF-Pro kit yesterday, so then I was playing with it last night to practice, and then ran another full round this afternoon after it had rained some more. As it stands now this is what I'm looking at:

FC - 5
pH - 7.8
TA - 60
CYA - 40
SALT - 3200
CH - 225 - This one says "red indicates the presence is calcium". However, mine turns a light shade of purple. The rest of the steps seem to hold true, and ignoring the color difference I come out at 225.

So based on that it's showing my CH and CYA are out of range.

For CYA it's telling me I should put 4 lbs, 8 oz of the dry stabalizer in. Should I use this stuff I have? My plan was to add 2 lbs in a sock in the skimmer, and then run more tests and compare with the store and see if they say anything about it. Then repeat until I get up into the PM ideal range.

For CH it's wanting me to choose Calcium Chloride or Calcium Chloride Dihydrate, but I don't have any idea what those are, so I guess I don't have any..??

Any information on this would be greatly appreciated. Thanks!

 

[AK-]

After that I started seeing info in the forums about how the liquid acid is better (although I really don't like working with it), especially for salt pools which I have. Can I use this stuff I got until it's gone, or would it cause problems?

Dry Acid is definitely appealing, but bad all around. As a byproduct you will introduce sulfates to the water. Sulfates are corrosive to concrete and metals, specially those high quality and expensive metals found inside heater and SWG cells like titanium. There is also some debate about the possibility of forming gypsum crystals if CH is high.

For CH it's wanting me to choose Calcium Chloride or Calcium Chloride Dihydrate, but I don't have any idea what those are, so I guess I don't have any..??

Living in Florida I don’t expect you to have any laying around… Calcium Chloride is ice melt (must be free of contaminants). They are sold as CH increaser in most places.

CH - 225 - This one says "red indicates the presence is calcium". However, mine turns a light shade of purple. The rest of the steps seem to hold true, and ignoring the color difference I come out at 225.

I have seem a discussion about it before. If I’m not mistaken it is something in the sample that affects the color but not the test… I don’t recall what it is… perhaps someone like @Newdude or @mknauss could shine some light.

For CYA it's telling me I should put 4 lbs, 8 oz of the dry stabalizer in. Should I use this stuff I have? My plan was to add 2 lbs in a sock in the skimmer, and then run more tests and compare with the store and see if they say anything about it. Then repeat until I get up into the PM ideal range.

In general stabilizer is stabilizer. I personally prefer to hung the sock in front of a return, but putting the sock inside the skimmer works.

 

[Newdude]

have seem a discussion about it before. If I’m not mistaken it is something in the sample that affects the color but not the test… I don’t recall what it is…

Metals.
Lifted from pool school :

• The sample may turn purple during the test, or go to blue for a moment and then turn back to red/pink. This is called a “fading endpoint” and is caused by interference from metal ions. If this happens, do the test again, but this time add five drops of R-0012 before adding any R-0010 or R-0011L. Remember to count the initial five drops in the total.
  In extreme cases, a fading endpoint may occur even when adding five drops of R-0012 at the start. If that happens, mix pool water with an equal quantity of distilled water, test that, and then multiply the result by two.

 

[mknauss]

If I’m not mistaken it is something in the sample that affects the color but not the test…

Metals interference. Sometimes best to use the fading endpoint procedure. See Extended Test Kit Directions Archives