TF-100 Here! Now where to start?

[Mapmgr]

Howdy,

For background, see my thread https://www.troublefreepool.com/threads/139190-Hello-from-OKC!-Rough-opening-and-chemistry

Stats from my TF-100 & Aquacheck Salt retest:

K1000 Chlorine Test	<= 0.5
K1000 pH Test	8.2
Free Chlorine	0.5
Combined Chlorine (1 drop plus 1 extra from above)	1.0
Total Chlorine	1.5
Calcium Hardness	200
Total Alkalinity (I was surprised that it was this low)	100
CYA (needed a taller tube )	< 20
Salt (Aquacheck strips) between 6.6 and 6.8	3210-3500 (3350)

Based on Pool Math, I have a good idea how much to add, but I'm not sure which out of what chemistry to hit first. I'm upset with myself in that I now believe my crumbling plaster is due to low calcium rather than having the lowered water freeze during the winters. [Edit] I have received a new SWG T-15, but have not yet installed it. [/Edit]



-- Glenn

 

[Texas Splash]

Glenn, even though it's a little tough to tell from the pics, your other thread speaks of opening with a green pool, or partially anyways. So that tells us you need to perform a SLAM (link below) to be sure all algae is removed. So with your TF-100, do the following:
1. Lower pH to about 7.2. Re-test to ensure it's there before continuing.
2. CYA must be at least 30. Anything less and that sun will tear-up your bleach. If you overshoot to 40, that's not the worse thing either. But get a sock soaking soon.
3. Increase FC to "12" and maintain it. If your CYA turns-out to be closer to 40, make your FC "16". Either way - maintain it until you pass all 3 SLAM criteria.

For FC testing, use the FAS-DPD (powder & drops). 10 ML sample with ONE generous scoop of powder. Mix and count drops until clear and divide by 2. Example: 24 drops = FC of 12.

After the SLAM is complete, then you can adjust other chemical levels and focus on any other issues you may have with the pool. Good luck!

 

[Mapmgr]

Thanks Texas Splash! Much appreciated.

 

[Mapmgr]

I'm having a little bit of progress, but the pH after initial change is barely budging. I mix the measured 34.45%/20 Baume Muriatic Acid into a bucket of about 2 1/2 gallons of water before putting into the pool.

05/26/2017 @ 0615 added ~28 oz 20 BE MA to pool. It was too dark to start with the acid the night before.

@1830 (6:30 pm), pH = 7.8; added 16 oz MA slowly to skimmer

@2100 (9 pm), pH = 7.5; TA = 90; added 16 oz MA to pool; pump was set to low speed overnight

5/27/2017 @0720, pH = ~7.4, instant TC = 0 (K-1000 test), TA = 90.

Between 0810 and 0830, slowly added the following separately via the skimmer, but may still not have had enough time and neutralized each other. I was concerned that there was no chlorine and we have a heat advisory today so I thought it best to go ahead and add some of the conditioner and some bleach.
- 3/4 gallon of Instant Pool Conditioner
- 1/2 of 121 oz jug of 6% Clorox
- 14 oz MA
Pump left on high speed.

@1130
Instant TC < 0.5
pH = ~7.4
FC < 0.5; could barely see the pink
CC = 0
TC < 0.5
CH = 200
TA = 90
CYA < 20, but cloudier than originally measured above, so there is at least improvement here. Guessing maybe 10-15 CYA.

I have not started slamming yet; I need to vacuum first which will require a filter cleaning afterwards, but I did not want to wash out any of the instant conditioner. I'm beginning to wonder if my pool is closer to 15,000 gallons vs quoted 12,000.

 

[Texas Splash]

Okay, so a few things to help you along ....
- It's almost always best to never add any chemicals directly to the skimmer if you can help it. Tends to complicate either the filter or might be an issue for the pump. Most products are slowly poured at the return jet(s), but there are a few exceptions. When in doubt, check the Recommended Chemicals page and it says how to dispense each product.
- Instant conditioner usually records quickly (the only benefit to its price), so by the end of today it should be at your CYA goal.
- No need to dilute muriatic acid. Just like bleach, you can pour at the return jets. Just do it slowly and carefully (splashing & fumes).
- For bleach, shop around for best value. You're using a 6% now, but Wal-Mart has their Great Value for $2.94 a gallon at 8.25%.
- As soon as you get the pH down to about 7.2, begin the SLAM (FC of 12) and you should be on your way.

Good luck!

 

[Mapmgr]

Okay, thanks. I thought I had read here in the forum to use the skimmer and pump to disperse the chemicals, but I must have read incorrectly. Thank you for the correction. I originally bought 2 gallons of the 6% based on the original thread response. Later in preparation for slamming I picked up three twin packs of Pool Essentials 10% for $6.44 with a 2017 date stamp at a WM close to where I work. The individual gallons all have 2016 dates and that is all the WM local to where I live has. Looks like I may need to stock up in a few more. I've learned to read the labels, though. Don't buy the "Reduced Splash" formula nor the "Clorox Outdoor Cleaner Professional" as they have other ingredients. Sam's Club has a triple pack of 121 oz 8% Sodium Hypochlorite "Performance Clorox" for $9.47.

 

[Texas Splash]

That's correct. Avoid anything that says "splashless" or "scented" unless you want a 12K bubble bath. I bought some bleach today and the Julian date code was something like "17 123" day which is about May 3rd. http://www.pps.noaa.gov/forms_guides/guides_aids_tools/julian-date-calendar.PDF

 

[Mapmgr]

LOL re bubble bath.

I think the installer lowballed the estimated gallons. They said it was 12,000, but treat as 15,000. According to the contract, max width = 15', max length = 32'. Shallow end is 3' but drops relatively rapidly to 8'. Assuming an average of 5.5' rounded to 6', the maximum gallons would be 21150.

I added the rest of the liquid conditioner for the full gallon, same with the 6% bleach and another 16 oz of MA. Four hours later:

pH = 7.4, maybe 7.35
FC = 0
CC = solid 0.5
TA = 90, possibly 85.
CYA = ~18 or 19; dot obscured right at the top of the tube, but it did obscure!

According to the bottle, the conditioner raises CYA 32 ppm per 10000 gallons which is different from PoolMath. Unless it raises further over night, I estimate the actual volume to be 17,300 +/- 500.

Will play more tomorrow.

 

[Mapmgr]

Finally done slamming! I had the CYA up to 30 and was bringing the FC to 12. Unfortunately during the work week it would get down to 4 so I started to run the SWCG during the daytime only to help maintain levels. Hard part was due to the crumbling and separation of the top layer of plaster for having too low CH (even though pool store said was in range), I had some algae hiding between the plaster layers. Water is crystal clear and passed overnight chlorine test. Still have some dark stains at the swimout and bottom of pool.

Now working on bringing up CYA and calcium levels.

How low does the chlorine level need to be for the pH and TA tests to be accurate? Corresponding Target FC level for a given CYA?

 

[mknauss]

To read an accurate pH the FC needs to be below 10

Follow the FC/CYA chart Pool School - Chlorine / CYA Chart to get your target FC for your CYA. Be sure that during the day you never go below minimum. So that means having a higher FC early in the day to combat the loss to sunlight and swimmers during the day.

Take care.

 

[Mapmgr]

Thanks for your quick reply!