Starting to get anxious

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duxthaman

0
Jul 28, 2016
26
Dallas, TX
Ok, so I pulled the trichlor tabs out of my pool last Saturday and have been testing my pool by myself ever since. The water is very clear, but my FC is being used up a lot (I know, it's 100 degrees out here in Dallas). My pool gets direct sunlight for a lot of the day.

CYA levels are still in the 80's, so I've been trying to get FC up to 9 or 10 morning and night. I've gone through three jugs of 8.25% bleach in ~5 days.

My main concern is that my FC dropped 2.0ppm two nights ago, and 1.5ppm last night. Overnight saturday and Sunday it did not drop more than 0.5ppm.

My water is extremely clear and I don't see any signs of algae, but I don't know how to explain my overnight loss other than algae being present. But it's weird that I wasn't having this issue the first couple days. I've been borderline obsessive testing my FC and getting bleach in there at least twice a day.

If I have to shock it, is it a cardinal sin to use the "Shock" that I have leftover from before I saw the light here? Or do I need to buy stock in Chlorox before I go to Costco and stock up?

Here's my latest readings from this morning:

FC-9
CC- 0
pH-7.9
TA- 110
CH-380
CYA- 85ish

That was after adding 36oz of bleach. FC an hour before that was 6.5. Tested at 10p last night and it was 8.0

- - - Updated - - -

I should also add, my FC was 8.0 yesterday morning. I added 28oz of Bleach after I tested. When I got home at 7p my FC was 6.5.

Don't know if that's normal given the heat and 9-10 hours of sunlight my pool gets.
 
mgmoore7 said:
I can't quite tell from your post if you specifically followed this Pool School - Perform the Overnight FC Loss Test (OCLT) to determine if you have something in your pool consuming the FC.

If you fail the test, then it is time to SLAM and it probably won't take very long since your water is clear.

If you were considering replacing water to reduce your CYA, do it before the SLAM.
Click to expand...

I'll do it once more tonight to make sure I follow the procedure to a "T". I am not going to replace the water since my CYA should start to come down now that I took the Trichlor out. Also, being as hot as it is, I lose water to evaporation and pump new water in once or twice a week (not a lot, but probably two inches at a time).

Is it okay to use the "Shock" (granular chlorine?) that I have to do this? Or should I go get a ton of bleach. I'm not around my house from 7:30a until 7p. Might be able to have my Mom come by and dump a gallon of bleach in the afternoon.

I'm just confused because I wasn't having this issue over the weekend. I've been very diligent getting bleach in the pool to keep that FC up. It's never dropped below 6.5, and it's usually around 8.

Oh well, will let you know what the overnight test results are.

Thank you
 
Your CYA won't come down since you have removed the Trichlor. It will just stop going up higher. Your CYA will only come down with splashout short of a drain/refill.

The shock will raise your CYA even higher (unless its Cal-Hypo).

And I wouldn't fret about an issue until you confirm it per Matt's note above.
 
All of the granular or puck varieties add something to the pool in addition to chlorine. Either calcium or CYA.

With a CYA of 90, your minimum FC is 7 with a target of 10. If you went below 7, then that could have been the opportunity for something to start growing.

Personally, I have found that I don't want to flirt with the minimum.
 
mgmoore7 said:
All of the granular or puck varieties add something to the pool in addition to chlorine. Either calcium or CYA.

With a CYA of 90, your minimum FC is 7 with a target of 10. If you went below 7, then that could have been the opportunity for something to start growing.

Personally, I have found that I don't want to flirt with the minimum.
Click to expand...

Ya I'm not trying to go minimum, but that's what happens during the day when I'm gone. And, yes, that's what I meant re: the trichlor.

I'm a little frustrated right now. My pool has been clear all summer. I took maintenance into my own hands because I didn't know what all was going in there. Now this...
 
+1 to avoiding minimum by 1 or 2 ppm. Especially when it is HOT and people are swimming a lot.

As mentioned, CYA will not evaporate. Only rain, splash out and carry out will lower CYA. Just be mindful that the PH test is not valid when FC is above FC is above 10 ppm.

Now, with your dallas water and those numbers your water is prone to scale. You have probably noticed it in your coffee pot, shower, etc. It is easy to prevent scale in your pool by managing your CSI. PoolMath will give you the number, keep it between -0.3 and 0 to prevent scale. Tweak PH and TA to move the number.

More here, Pool School - Calcium Scaling

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duxthaman said:
Ya I'm not trying to go minimum, but that's what happens during the day when I'm gone. And, yes, that's what I meant re: the trichlor.

I'm a little frustrated right now. My pool has been clear all summer. I took maintenance into my own hands because I didn't know what all was going in there. Now this...
Click to expand...

There is a bit of a learning curve here but once you get past that you will love your pool. Hang in there.
 
duxthaman said:
Ya I'm not trying to go minimum, but that's what happens during the day when I'm gone. And, yes, that's what I meant re: the trichlor.

I'm a little frustrated right now. My pool has been clear all summer. I took maintenance into my own hands because I didn't know what all was going in there. Now this...
Click to expand...

So, you just need to add enough the night before or before you leave to be sure that you don't lose more than you put in.

Lets follow this though and give you a close to real world scenario (only once you pass the OCLT)

-Lets say that each day in this summer heat and Texas sun, you lose 4ppm of FC (that would not be uncommon)
-Assume that you test FC at 9pm and it is 8ppm (your target for a CYA of 90 is 10ppm)
-Add enough chlorine to the current FC value to get to the Target + Daily Loss (8ppm + (10ppm-8ppm) + 4ppm) = 6ppm. This will bring the total FC to 14ppm.
-Next day if you had 4ppm loss of Chlorine, at your 9PM test, the FC should be 10ppm. If it is more than 10ppm, then you did not lose 4ppm for the day. If it is less than 10ppm, you lost more than 4ppm for that day. Over time, you will learn the average since it does change day to day based on weather, use and temperature. Since you were basing your calculations on Target, not minimum, you should never go below the minimum of 7. That minimum gives you a 3ppm fudge factor.

If you find that you regularly don't lose 4ppm a day, then can add 3ppm and vice versa is true.


I hope this helps. The key is to always add as much as is being lost. Additionally, you will find that if you have a heavy swim day such as a all day swim or party or something.... add 2-4ppm additional before and/or after. It will ensure that during the high demand for FC, it won't go below the minimum but rather stay near Target.

I know this is alot, you will get it and it will be great.
 
That's great info, thank you so much. I've been adding enough to get to target...will shoot for the over from now on. I lost 2ppm today between 8a and 7p. Will keep tracking that.

Hopefully mybovernight loss loss test come back ok. I did swim Monday night so that may account for some of the loss overnight then.

About to test, add bleach, and then test again before sun gets up.
 

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My tests last night, after adding bleach an hour earlier, were FC-8.5

Tested this morning and I got varying results. I think I'm not doing a good enough job getting the water out from when I clean the test tube out or something. My first test was FC-7.5, 2nd was FC-6.0, switched tubes and 3rd was FC-9.0, washed thoroughly and dipped completely in the pool and rinsed again and tested FC-8.5.

I know the test kit says its not important the exact amount of powder, but is that true? I'm doing one heaping blue spoon.

Either way, I think I passed the overnight test but I'm going to do it again tonight. My CYA is 80, so I'm adding enough bleach to get to 11ppm since I think I lose about 2ppm during the day.
 
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