Couple questions regarding chemical levels. Still learning...

[Heydeman]

Based off my other two threads, I replaced about 1/2 my water and got CYA down to 35-40. Before I found this site I had purchased some dichlor Bioguard shock from pool store, after they repeatedly told me the shock contained no CYA...I called Bioguard to confirm this and was told the indeed bioguard smart shock contains CYA (supposedly 3.6ppm CYA for every 10ppm Cl). Strike 1 pool store.....

Before I went to return bioguard shock to pool store I tested my water myself.

CYA 35-40, FC 8, CC 0, TA 110, CH 215, Ph 7.4.

For sh** and giggles I had the pool store run there test again about 1.5 hours later.

CYA 42, FC 5.1, TC 4.7, TA 93, Adjusted TA 80, CH 226, ph 7.5

They wanted me to increase my adjusted TA to the 125-150 range. What exactly is adjusted TA compared to regular TA first of all? Everything I have read for a fiberglass pool, a TA in the range of 70-120 is optimal. Is adjusted TA something to worry about, or am I fine with my tested TA in the 90-110 range? I suspect adjusted TA is used to sell more chemicals. But wanted to get the skinny.

They then wanted me to add another 2 lbs of smart shock to the pool.....something about chlorine lock...which from what I've gathered is a bunch of B.S. ****, my FC level was at 4.7 (well within the range taking into account the CYA/Cl chart and I've always tested 0 for CC even while slamming. I just got done SLAMMING, and passed the OCLT test 1.5 days ago with flying colors (0 ppm loss, clear water). I've been maintaining cl between 3-7 ever since.

I didn't purchased anything from the pool store. But I wanted to confirm that my current chem levels are doing fine, and as long as my cl stays within the 3-7 range based on my 40ish CYA I'm good.

Thanks for the help everyone, I'm new at this and still trying to figure things out. Getting a pretty good education over the last week, no doubt!

 

[timerguy]

You're learning quick! It took me a year after buying my house with a pool to learn about cya and how it screws up your pool if too high. The previous owner used nothing but Trichlor tabs and dichlor shock. After I got my K-2006 testkit and learned how to do a dilution cya test I found my cya was over 340 instead of the 40 Leslies had been telling me for over a year and 3 major algae blooms.

 

[PharmerAnthony]

Confirmed. A pool store tried to sell me some $30 Arm and Hammer basically bio guard balance pack whatever to increase my adjusted alkalinity however it was not necessary. I've never heard of this chlorine lock perhaps someone else can chime in?

 

[Richard320]

Heydeman, your numbers are fine. How does the water look? That's the big test. Nobody but us cares how perfect your numbers are - people are impressed when they see a crystal clear sparkling pool that doesn't smell funny or burn their eyes or dry their skin.

PharmerAnthony - "Chlorine Lock" is a pool store euphemism for "overloaded with CYA." In brief, the CYA level is so high that to get enough FC in the pool to kill the algae requires powdered chlorine by the bucketfull. The problem is that if the first bucket doesn't kill the algae (it probably won't), you've raised the CYA even more, so next trip they sell you two buckets, and the time after that three, and then they whip out the dreaded "High TDS, you need to drain" answer.

 

[jblizzle]

chlorine lock is a buzz word that they seem to use when they have no idea why the pool wont clear ... usually because your CYA is too high. But, based on their test results, I have no idea how they would come to that conclusion because that indicates things are fine.

 

[Isaac-1]

To answer your question about adjusted TA, I am really not sure, but think it is some combination of TA and acid demand, and I really don't care. TA is the last thing you should worry about with a pool and target numbers are really just ballpark one size fits all estimates to minimize pH drift, the problem is that target number makes certain assumptions about things like the pH of your fill water, pH of wind blown dust. etc, that are not always true for everyone.

Ike

p.s. note this comes from someone with extremely acidic fill water, mine averages around 6.6-6.8 some nearby munipical wells are as low as 5.8