First time back this year, levels seem bit off

[Jamie A 14]

Pool looks pretty good, considering we just got back from a week vacation and the 90+ degree weather. However, looked slightly cloudy yesterday and added a bunch of chlorine last night (didn't test anything, too tired!). Did test this evening though:
FC=1.6
CYA=20-30? This test still gets me!
PH=8.0
TA=210
CH=170
I plugged all this in to pool math, but I'm not sure what to add when. Can someone simplify and decipher, telling me what to do to get things balanced?
thanks!!
jamie

 

[Jezza]

You need to deal with the pH first- it could be higher- so use Pool math and add MA to pitch for 7.5, test 1/2 hour later and repeat of necessary.

You could have an algae issue so performing the OCLT would be a logical next step.

And use the 10ml sample for the FAS DPD test - it will save you a heap on reagents.

Also read through this Recommended Pool Chemicals

 

[MarianParoo]

We want YOU to learn how to do it yourself!!!

First off, use a 10ml water sample for FC/CC. Then multiply your drop count by 0.5 (divide in half) instead of 0.2.

If your CYA is between 20 and 30, count it as 30.

Then, going into PoolMath, use your current numbers for "now" and "goal" for all but FC and pH. What do you get to bring pH to 7.4 and FC to 4?

 

[Texas Splash]

Definitely bring the pH down a bit. But shortly after allowing the acid to mix, bring that FC up right away. I would increase the FC to 12 if it were me. Do that now with bleach and just before bed take your first OCLT reading. Seeing as how your FC was so low when you returned, I suspect you have algae starting, but the OCLT should help confirm that for you. Also make sure to test/post your CC next time for us as well. That helps paint the total picture.

 

[Jamie A 14]

Thanks, I added chlorine (not enough to get it to 12), and tiok reading 1/2 hr after adding and will test first thing in the morning to see if indeed an algae problem. I plan to go get some ph reducer tomorrow to bring that down. Then, should I worry about CYA or not? Last year it was always too high, due to our use of the Frog Cycler, which we've discontinued last summer.

 

[Jamie A 14]

So, I did the OCLT, FC WAS 4.5 last night and 4.5 this morning. CC was <.5. I did add about 1/2 gallon of chlorine just for good measure (it was rainy/cloudy most of the day) and tested again at 5:30 this afternoon just to see and FC was 4, CC was 0. I also added pH reducer and the pH measured 7.6 from 8.0+ (tested about 1.5 hrs after adding). Strange that the FC would not be higher than it was--but, the sun did come out in the afternoon for a while and we had a few boys swimming. Water looks great, very clear (but I've spotted a few of those "water bugs"). So, I guess the plan for tonight is to test FC after sundown, and then add what? To target or SLAM? I also was wondering what kind of chlorine replenishment routine y'all follow, as I feel sort of haphazard, adding daily, or every other, sometimes testing, sometimes not. Sorry to ramble on, you'd think I'd be more ontop of this after 4 yrs with this pool!! Thx!!

 

[Jezza]

Well from that it sounds like everything is fine. You could bring the FC up to say about 10 if you wanted to repeat the OCLT to make sure.

From how you have described it - with the addition of 1/2 gallon of chlorine- it sounds like your FC consumption during the day is fairly normal.

The way to go for the future is liquid chlorine or bleach- the good thing is that it doesn't really come with excess baggage such as CYA or calcium- just a bit of salt which is nothing to worry about.

It is easier to use Muriatic Acid (MA) to bring pH down if you feel happy to use it.

 

[Jamie A 14]

Thanks. So, I just tested again the FC, 8:15 pm, haven't added anything more since earlier and it was 4-4.5, CC = 0. Should I add more then? Bring to a 10 like you said? I think I will and then check in the morning just to be sure. And, I use only 10% chlorine, but was just wondering what most people's "routine" is. Nightly additions or every other, and is it really necessary to test each day or no?

 

[Jezza]

Yes I would bring it up to 10 FC just as a confirmation. Everybody does something different- but many take the view that if they add and test at night then it gives the chlorine in the absence of sunlight a chance to oxidise any organics. On the other hand you need to make sure that your FC levels always stay above the minimum for your CYA level. I have an SWG so I run it for a few hours at night during summer and a few hours first thing in the morning. I would be testing every day until you can ascertain a pattern for your FC consumption.