High CYA, High TA, Low PH

[NiceGuyEddie]

Excellent site, pushing me to learn and start to take control on my own, rather than continously running to the Pool Store. Found your site late last night looking for answers as to why I could not get my PH to come up. Did some reading and tried aerating to raise the PH and its working. I don't have one of the recommended test kits, yet, so here are this mornings test numbers from the store. I purchased a Pentair 78DPD+ kit this morning, it will have to do until I can get one of the recommended ones.

17K Gallon, IG Vinyl, Sand Filter, with auto cover in Wichita, KS
FC - 3
CC - 0
PH - 7.4 - had been stuck at 7 since opening, even with over 40 pounds of soda ash this season. Turned all jets up late last night to get this rise, will be buying some PVC parts tonight to aerate more.
TA - over 300 - she lost count of the drops at that point.
CH - 250
CYA - 100
Temp 94F

Pool calculator says to replace 60% of my water - cannot do that all at once due to water restrictions and cost.
I am planning to use the aerate, acid, aerate method to decrease my TA.

BUT, my question for you guys is what should I be working on first? I know that my CYA and FC are issues, but do I need to fix the TA first? Or can I just get the PH to a normal level, get the FC right and worry about the TA later? Not sure I can fight both issues at the same time.

Planning to shift to the BBB method after I get the chemicals I've already bought used up.
Thanks for your help.

 

[NiceGuyEddie]

Whoops.

Water is slightly cloudy, not green, but milky. Can see the main drain covers in the 6 foot end, but barely.

I use TriChlor tabs and DiChlor shock right now. Till they're gone.

 

[woodyp]

Welcome to TFP! Ta is the last thing on the list and will gradually be reduced as you maintain Ph at the proper levels. What kind of pool and SWG or not? Please list your pool equipment in a sig line like mine at the bottom by using user control panel at the top of the page. Cya can be fixed by STOPPING using trichlor pucks and dichlor shock and switching to bleach to begin with. But as it doesn't evaporate, water replacement is the only option. NO, you don't have to do it all at once nor do we recommend that. It will require a series of partial drains and refills. Just keep the tabs you have left on hand to maybe use during while gone away on trips or vacation. Your FC is way too low for your CYA level---see the chlorine/cya chart. And (psst.......) your CYa is probably well OVER 100.

 

[jblizzle]

Welcome to TFP!!!

Well, the tabs and the dichlor are what are causing your problems!!! They add FC (which is consumed) and CYA (which builds up) and are acidic which lowers your pH.

The correct course of action would be:
1. Order one of the Recommended Test Kits
2. Read Pool School to understand the chemicals. Start with these:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool
3. Replace water to get your CYA into the recommended range of 30-50ppm
4. Follow the SLAM Process to eradicate the algae in the pool.

BTW, the pH is fine and TA is WAY down the priority list.

 

[NiceGuyEddie]

Please list your pool equipment in a sig line like mine at the bottom by using user control panel at the top of the page.

And (psst.......) your CYa is probably well OVER 100.

Thanks guys. I thought I had it all listed, guess I missed the fact that I am using a Tab Chlorinator, rather than an SWG.

Read many of the pool school articles last night, and some more today at work (not getting a whole heck of a lot done today).

She actually told me my CYA was 100+, probably lost count on that one too. Too busy talking to me.

 

[JohnN]

The problem with the CYA test is that is shows anything over 100 as 100. When you get your test kit, you should do the CYA test using the dilution method, using 1/2 pool water and 1/2 tap water and doubling the result. If you still get 100, that means your CYA is over 200. Since your pool is cloudy, you will have to follow the SLAM process, which is almost impossible with such a high CYA. For a CYA of 100, shock level (is it still called that, or is it SLAM level?) is 25 ppm FC, and if your CYA is 150 you have to get to 33 ppm FC. If your CYA level is 200, to SLAM your pool you have to get up to 41 ppm FC and never let it drop below 15 ppm.