Test results and adding chemicals

[crockettjeanne]

Good morning pool people!
I have read many threads on the order of adding chemicals but I am still not sure. Below are my test results from this morning and then the list of the chemicals and amounts to add as recommended by my pool math app. So any advice on order of adding and wait time between is greatly appreciated. And please feel free to check me on the additions.

TC= 3 OK
CH= 150 (need to add 34 lbs calcium chloride)
TA= 60 OK
CYA= 20 - black dot never disappeared from view (need to add 6lbs,3 oz Dry stabilizer to start) How long until I retest?
Chlorine= 3 OK
PH= 8.2+ (need to add 2 quarts,3 cups muriatic and test again)
Salt - 2900 - (adding 40 lb bag salt)

 

[Texas Splash]

If your water is crystal clear, the I would say the following:
1- Add 50 ppm worth of stabilizer to increase the CYA closer to 70 since you have an SWG.
2 - Increase the FC to about 5-6 ppm for today with liquid chlorine. It could use the help.
3 - Lower the pH to about 7.7-7.8
4 - Increase the CH as you noted.

If however your water is cloudy or you suspect algae, only increase the CYA to 30 and perform an Overnight Chlorine Loss Test. I would still increase the FC today with liquid chlorine and lower the pH though.

 

[crockettjeanne]

Thanks! Water not cloudy, but I do have a few black spots I had to rub the chlorine puck on to "erase".

 

[Texas Splash]

not cloudy, but I do have a few black spots I had to rub the chlorine puck on to "erase".

That is something to watch. They could be tannin stains from junk falling into the water if you have trees nearby, or it could be organic/algae. Let us know if you continue to have problems with those.

 

[crockettjeanne]

I am glad I waited on the salt. Is it the calcium that is causing the increase in ppm?

 

[crockettjeanne]

This morning:

TC = 5+
PH = 7.2
CH = 325
TA = did not retest yet
Salt = 3200 (did not add the salt and still got this level.
CYA = have not retested, but stopped adding after 4lbs dry stabilizer as it seems to be raising my salt level

The water still clear, Yay! Still see the black spots, but they are typical when I let the chlorine get low and I just scrub with the puck and tool and they go away and stay away for the season.

I did not add liquid chlorine, but did jack up the SWCG to 100%. I just backed it off to 75%. Is that good for 95 - 98 degree days?

 

[mknauss]

CYA does not add to your salinity. The calcium chloride did add a minor amount.

 

[crockettjeanne]

Ok, so I am safe to continue to add stabilizer to increase CYA to 70?

 

[Texas Splash]

Ok, so I am safe to continue to add stabilizer to increase CYA to 70?

You can. The only reason you would not increase the CYA is if you think you might have algae. Those black spots could be alarming, If you are concerned about algae you could do an Overnight Chlorine Loss Test to be sure. Otherwise, you can add stabilizer at any time.

 

[crockettjeanne]

I watched TFPs YouTube video on the relationship between FC and CYA and I think I may be looking at this wrong. Before recent chemical additions I did not have significant chlorine loss per day. Usually run SWCG at 50/60 % and run pump 8 hours a day and still keep chlorine at 2 or 3 and I have never had CYA above 30. I have full sun most of the day in the Georgia sun. Now after following the pool math, the chlorine at 7.5 can be smelled on my skin after swimming its so strong. I feel like I am making too many changes too fast. Help!

 

[jeffchap]

That chlorine smell is combined chloramines (CC) not free chlorine (FC). This means there is something in your water that is being killed by the chlorine.

How are you testing? You are posting TC but neither of our recommended test kits measure TC (although it can be calculated, but it's meaningless).

Are these pool store test results?

 

[crockettjeanne]

These are results from my TFP pool kit. I did the ppm and FC is 7.5 and CC is 0. Doesn't that mean Total Chlorine is 7.5?

 

[crockettjeanne]

 

[jeffchap]

These are results from my TFP pool kit. I did the ppm and FC is 7.5 and CC is 0. Doesn't that mean Total Chlorine is 7.5?

Yes, but presented as TC, we have no idea how much is FC and how much is CC. So please post them separately.

 

[crockettjeanne]

Did I miss anything? And the pool itself does not smell like chlorine, only smelled it on clothes and skin after swimming and this is not the norm.

FC 7.5
CC 0
CYA 40
PH 7.2
TA 50
CH 350
Salt 3200
pool temp 91

SWCG at now 50% (was 100% as prior recommendation was to increase chlorine)
VS running 8 hrs at 2500

 

[Texas Splash]

Aside from a low CYA for a salt pool (70 recommended), your numbers look very good.

 

[IceShadow]

Increasing the CYA will decrease the active chlorine in the pool, and so may knock down some of the "chlorine" smell. That's just free chlorine doing what it's supposed to on your skin's natural sweat/oils/etc.

 

[jeffchap]

I think the two guys above nailed it. Most of us with SWGs keep our cya 60-80. This helps prevent burn off from the Sun and keeps your swg from having to work as hard to replenish the chlorine.

I like to keep my FC level at 10% of my CYA, if you so if you raise your CYA to 70 and keep your FC where it is now, it will be perfect.

 

[jedigrover]

+1

Watch those black spots. It sounds like black spot algae (actually a cyanobacteria). I've gotten it when my salt cell died and I wasn't testing often enough to know. Now, it will try to come back anytime the FC goes too low (even if FC is 2 or 3ppm). The chlorine puck is a good way to address them if you only have a few. My opinion is that you are never truly rid of it. It's roots are down in the plaster, protected by a waxy slime cap, and it's just waiting for an opportunity to invade. So be vigilant of keeping your FC up in the range you need to be effective considering your CYA.

Personally, I run my pool with CYA of 60 (probably due to some PTSD from having CYA way too high some 15 years ago and the struggle that ensued), and try to keep my FC at 6. That works for me. What works for you / your pool will vary. Pools are like people, they are all a little different (some are a lot different).