Time to replace sand?

[jonno]

Morning numbers:
FC 18.5
CC 2.0
pH 7.2 (added another pint of m. acid)
TA 180
This morning the FC was much higher than in the past and I think it may be affecting the TA test. Today the TA test water turned from green to briefly bluish to pinkish. All other days the TA test water has changed from green to briefly purple to a deeper red.

The pool water has a little more visibility (almost 30") and the shade of green is lighter so the shock is attacking the algae and POPP seems to be paying off.

The recycle man has dozens of bleach bottles to pick up this morning, but my 5 gal. carboys arrived last night and today I'm making my first run to fill them with 5 gal of 12.5% bleach.

• Given that my CYA is between 100-200, can anyone give me a ballpark estimate of how much bleach I'll be using each week to keep my chlorine in the 8-15 target zone (once my water is balanced and clear)?

I'm using a 9 gallons/day dosage now until the FC holds within 1 ppm from one evening to the next (once I switch over to 12.5% bleach, the 9 gallons will convert to just under 4.5 gal).
Thanks!

[jonno]

Evening numbers;
FC 9.5
CC 1.5
pH 7.1
TA 170
Dosed another 9 gallons. Visibility is better - I can actually see the return port.

[jonno]

Morning numbers
FC 25.0
CC 2.5
pH 7.2
TA 190? weird colors again (FC so high?) Trace amounts of foam (less than past days), visibility seems to be improving, and green coloration is lighter.

[jonno]

Although the FC numbers are looking good and the water is improving, the TA is staying in high (170 to 190) despite constant aeration and regular doses of muriatic acid.

• Should I continue with the acid to keep it to 7.0 even if it means adding muriatic acid every day or two?
• Is there any risk of the pH or TA test colors being off because of the high FC?

Thanks,
John

[jonno]

Bottom comes into view!! First time this season I could see my brush making swaths across the bottom as it stirred up the algae - I could see all of the shallow end and halfway into the deep end. What a huge difference in 12 hours! This is so encouraging after weeks of POPP. Evenings #s are:
FC 13.5
CC 2.0
pH 7.1
TA 190
Can any of the experts answer my questions in the last post?

[aylad]

[*]Should I continue with the acid to keep it to 7.0 even if it means adding muriatic acid every day or two? [*]Is there any risk of the pH or TA test colors being off because of the high FC?

The pH may register falsesly high when your chlorine is above 10 ppm. The higher chlorine should not affect the TA test colors. The ratcheting down of TA can be a very lengthy process, and it is slower in your pool because your pH is staying low before each acid addition, so you're not able to drop the alk very much with each addition. If you had some form of aeration in the pool (fountain, etc), the pH might rise a little higher each time, allowing you to make more progress with each acid addition.. I would continue to work on it, using the method that you're using, until you at least get it down to the 140 range.

My pool is maintained with 80-90 ppm of CYA, and I use approximately 4-5 of the large jugs of WalMart bleach weekly to maintain 8 ppm in my (roughly 29K gallon) pool, to answer one of your earlier questions. (I've been working nights this week and somehow missed a whole page of your thread..sorry!)

Glad to see you're seeing progress on your pool. Hang in there--it will all be worthwhile in the end!!


Janet

[jonno]

Thanks Janet. The water is getting better. It is still very cloudy, but that is an improvement over the opaque murkiness of the past month. I still can't see the bottom of the deeper areas, but I could make out a dark clump of leaves about 5 feet down that I then scooped up.

This evening the FC is 17.0 and CC is 1.5. I know though that it is far from the goal of losing 1 ppm of FC per day and 0.0 CC.

I'm still following Ben's prescription to dose 9 gallons of bleach a night. When I put in 9 gallons of 6% bleach tonight, it added 21 ppm of FC to the current level of 17.0 for a total FC of almost 38 ppm. Is that level okay? FYI: My CYA is somewhere over 100 (the black dot disappears very quickly, far before the 100 mark).

• Question: Should I be altering my dosage to target a nightly FC level or continue with the 9 gallons/night dosage?

My pH color is hard to match but there's a hint of purple that may line up with 7.4. But, you pointed out that pH colors can appear falsely high when FC is over 10 ppm. I'm going to hold off on adding any more muriatic acid pending expert advice.

The TA is 170. I found another aerator and will hook it up tonight to add to the ripple from pointing the return upward.

Thanks for guiding me through this ordeal.

John

[Watermom]

I think I would see what my cl reading was before adding bleach and then make a decision. Taking cl up to 38 is pretty high for a vinyl pool. I would probably not take it any higher than 25ppm.

Keep working on lowering TA. If you don't work over the weekend, see if you can test as many times per day as you can and each time, take the cl back up to 25ppm. Every hour or two or three would be great. No such thing as testing and dosing too often when you are trying to clear a pool. If you can do this for the next two days, maybe you can turn the corner.

EDIT -- Since you have the Taylor K-2006 kit, your pH test will be accurate if the cl level is lower than 15 instead of 10 like some other kits. So, check your pH as soon as your cl drops below 15ppm.