Bad test results, from rain water?

Amama

Member
Jun 19, 2017
22
Holden, MO
Test results a couple days ago:

FC - 2.5
CC -5
pH - 7.6
TA - 200
CH - 310
CYA - 35

Test results this morning:
FC - 0
CC or TC - 0
TA - 185
pH -7.8
CYA - 0

It has rained a lot here recently; the pool was too full and was losing a little bit through the skimmer, but is that enough to lose all the CYA? That doesn't make sense to me. I'm using the Taylor K-2006 test kit.

We put a half gallon of liquid chlorine in yesterday and ran pump before swimming. I feel like I should have the hang of this by now, still feel like I don't know what I'm doing with the pool, and spending a lot of time testing/adding chemicals, buying more, etc.
I'm down to the second bottle of CYA reagent that came with the kit.

Are there certain things we'll need to do automatically after large rains?

1st step? Should I start with CYA and add enough to get up to 40? I was nervous about getting too high.
Thank you for your time.
 

pooldv

TFP Expert
Platinum Supporter
LifeTime Supporter
Moderator Emeritus
Aug 10, 2012
25,412
FL panhandle
No, the FC was too low and bacteria grew in the pool and consumed your CYA. Possibly converting it to ammonia. It is important to always maintain FC above minimum for your CYA, [FC/CYA][/FC/CYA], to keep the pool sanitary. More here, ABCs of Pool Water Chemistry.

With CYA at 40, always round up to next 10, your FC should never drop below 3, [FC/CYA][/FC/CYA].

To check for ammonia raise FC to 10 ppm and retest in 10-15 minutes. If it is 0 repeat until FC holds at 5 or more. Then add 30 ppm CYA, adjust pH to 7.2 and SLAM Process the pool to kill the algae and bacteria.
 

jm1

Bronze Supporter
May 6, 2016
31
Burlingame CA
When I was starting to come up to speed on this, one of the bits of advice I found here was to pour liquid bleach, slowly, in front of the jet while running to disburse (and NOT in the skimmer, which can damage). The advice on CYA is put it in a sock, and let the pump run for awhile (and don't backwash).

Short answer: yes, unless there is a specific instruction not to, I always keep pump running to get the added items dissolved/spread out, and I keep the pump going until the next set of tests (when the tests are close together in time like pooldv's advice above--not when the next test is 2 days away).

Good luck!
 

Amama

Member
Jun 19, 2017
22
Holden, MO
One more question, pooldv, you said "Then add 30 ppm CYA, adjust pH to 7.2 and SLAM the pool to kill the algae and bacteria."
I've read I need to wait a week after adding to get accurate CYA levels, so am I getting the pool to 30ppm over that week before adjusting pH, or just adding the CYA now, checking in a couple hours and right away adjusting the pH, then SLAM?

Hope that made sense, thanks
 

pooldv

TFP Expert
Platinum Supporter
LifeTime Supporter
Moderator Emeritus
Aug 10, 2012
25,412
FL panhandle
No, just squeeze the sock a few times a day to help it dissolve faster. The wait a week is only if you add it to the skimmer and it is caught in the filter. And That is only for testing purposes. SLAM Process can start asap.

So, adjust pH, add 30 ppm CYA to a sock and start SLAM Process.
 

Amama

Member
Jun 19, 2017
22
Holden, MO
Finished the slam the other day, free chlorine isn't dropping much overnight.

Confused about the CYA level, seems like I should be able to check it once and it should stay pretty constant. I do the same thing each time, but it changes. It was 50 the other day, today was about 35(so I think I round to 40).
FC-7.5
CC-.5
pH -7.4

The water might look a little cloudy even though the chlorine and pH seem fine? I'm still learning the clear vs cloudy. It's definitely not greenish or dirty looking.

Are the numbers fine?
 

Teald024

TFP Guide
If you can't decide if the pool water is clear or not, then it's NOT clear. Once you have seen clear, there is no mistaking it... if you threw a dime in the water, could you see it?

The numbers look OK, but that doesn't tell the whole story.

What was your OCLT result? Is the water clear? Can you post a pic of the pool?
 

Amama

Member
Jun 19, 2017
22
Holden, MO
Yes, you can see a dime and I can see the bottom well. It just didn't seem as clear as last week, but it has way more chlorine now than it did a week ago (FC was 1). I can post a pic.

What is OCLT?
 

kcindc

Gold Supporter
LifeTime Supporter
TFP Guide
Sep 2, 2011
1,299
Fairfax, VA
FYI, the CYA test can be difficult. It is light sensitive and you need full sunshine, back to the sun, vial at waist level. I like to pour it to the first line, check for the bot, pour to the next line, check for the dot, etc. You can pour the contents back and forth if you are unsure. All values are rounded up to the nearest 10, for example, if the result is between 30 and 40, you need to round the result to 40.

You can save the CYA sample for another pair of eyes if you need a second opinion.