Does my FC usage seem normal?

[azkevman]

I have been keeping a log of my testing since my drain/refill last weekend. I am struggling with staying above the min of 4ppm for my recommended CYA of 50. I performed the OCLT on Sunday after bringing my FC to 8, which remained at 8 the next morning.
Monday night my FC had dropped to 3.5. So I added ~90oz. of 10% to bring it back up to 8. Tuesday night it again was 3.5, so in an attempt to not go below 4 by the next evening, I added ~96oz of 10%.

Once again on Wednesday night (last night) my reading was 3.5. I figured, OK I am going to get ahead of this 3.5 reading, and added a full gallon of 10%. Went out this evening to see where it was....and again I am at 3.5!!! It seems like no matter how much bleach I add, I keep ending up at 3.5 the next evening.

Since I am never supposed to let it get below 4, am I at risk for algae when it drops to 3.5?

The water looks extremely clear, and we have had the hottest days of the year so far this week (yesterday was 114°, today was 112°, and it's 107° right now at 10:15pm)

My numbers tonight:
FC: 3.5
CC: 0.5
pH: 7.7

I added 70oz. of 10%, waited 30mins and retested and FC rose to 7.0. I am going to add another 96oz. of 6% tonight to bring it up to 10ppm...

Does this seem normal based on my CYA, temps, etc? I am basically going through a gallon of 10% a day at this rate...

 

[jblizzle]

lol. I can just imagine your thought when 3.5 kept showing up.

That does seem a little high on the daily loss with a CYA of 50ppm. From your last test it sounds like the FC is not getting as high as you expected.

I might suggest raising it up to shock level and try the OCLT again ... won't hurt anything to try right? Maybe there is a little something still in the water. Any nooks and crannies to check?

Posted from my Droid with Tapatalk ... sorry if my response is short

 

[azkevman]

I swear it's like groundhog day or something...maybe I have to keep reliving it until I figure out the secret!

So I added the additional 96oz. Of 6% and retested. Now reading FC at 9.5ppm.

I will try the additional OCLT at shock level this weekend...thanks for that suggestion

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[azkevman]

I did a normal OCLT again last night and passed with a loss of 0ppm. So, it appears consumption is definitely only occurring during the day from loss to sun & swimmers in the pool. The pool gets about 10 hours of direct sunlight, and the water temp this time of year is usually around 92°-94°...so maybe it is normal to consume that much a day....I'm not sure??

Also I added acid to lower my pH to 7.2 4 days ago, and it has increased daily back to 8.0 as of this morning, is that a normal rate for pH to climb?

 

[Richard320]

If it's been that hot, I bet you've had a lot of sweaty bodies in the pool. That will use up a lot of FC.

pH climb sounds reasonable if you have high TA. You haven't posted a full set of results here, so who knows?

 

[azkevman]

sorry, as of my last full test a few days ago:

TA: 110
CH: 140

Just added acid again this morning to lower Ph, so expect TA to lower to around 100

CYA was last checked Sunday after refill was complete, and registered at 50

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