First Test with K-2006C Kit

[picchu55]

Just did my first test with the K-2006C test kit, and I wanted to confirm what I think I need to do.

Test results: 7.8 FC, 0.4 CC, 7.7 pH, 120 TA, 260 CH, 100 CYA in 78 degree water.

Here's what I think I need to do:
Stop using the 3" chlorine tabs in a floater so my CYA doesn't go any higher
Lower my TA to the 60-80 range

However, the calculator in the pool math app says I'm looking at about 2-2.5 gallons of 20 baume muriatic acid to lower my TA that much, and it shows that would result in a pH drop around 3, which is obviously bad.

Am I doing the calculations wrong? Should I be partially draining and refilling to drop the CYA before messing with anything else?

Something else to note: we did take a water sample to our local Leslie's store to see what their tests said prior to getting my kit. Their test shows the TA at 90 rather than 120 (everything else was much closer to my test). Judging from other posts, it seems like I should trust my kit over the store test, but I still wanted to mention it.

Thanks in advance!

 

[IceShadow]

For the TA test: wipe the tip of the dropper with a damp paper towel before the test and after every drop for the next 3 tests. Some of them build up a static electricity charge that makes the drops too small and the test read high.

You are right on the water exchange due to CYA levels. Before you do, try another test with half pool water and half tap water. Multiply result by 2. Your CYA could be over 100.

 

[Richard320]

Don't worry about the TA. That number will change if you replace any water to reduce the CYA. All you need to do is keep the pH in range and TA will slowly come down. No special effort needed.

Dustin's got you covered on the TA test interference.

Her's more on the CYA dilution test, Step 8

When testing FC, you can use 10 ml water and one scoop of powder then divide the drops in half. 10 drops= 5 FC, 13 drops = 6.5, etc. Saves reagent and is precise enough for us.

 

[picchu55]

@IceShadow I will make sure to wipe the dropper tip with a damp paper towel next time I test the TA. Thanks for the tip!

@Richard320 Thanks for the tip on the FC testing. That will definitely help save reagent.

For the CYA levels, I went to do the diluted test and came up with a result between 30 and 40. Figured I did something wrong, so I repeated it. Same result. Did another regular (non-diluted) test and came up with 70, which matches the diluted test. I did have to add some water for the first time in a while, but not that much. Will CYA levels fall proportional to the amount of water I added? If so, then I must have screwed up my first test today, because there's no way I replaced 30% of my water to drop from a 100 to a 70.

Plan to repeat my CYA test tomorrow morning before it rains and see if I can repeat my 2nd set of results from today. I knew my love of chemistry in school would come in handy one day! These test kits are fun!

 

[IceShadow]

The CYA test is one of the hardest. The trick is lots of indirect light. The brightest space you can but not with light directly on the tube.

At 70 I would still exchange water. Just only about 1/3 or so.

 

[picchu55]

CYA was at 70 again this morning. I must have screwed it up yesterday.

It's supposed to rain all weekend here. After it rains, I'll start working to get my CYA lowered.

 

[Richard320]

70 CYA is manageable as long as you don't have any algae. Not ideal, but neither is having really high CH and people manage with that, too.

If you have a way to divert rain into your pool, do it. I route a downspout to my spa and use it as a settling basin. Just make sure any dust on the roof has been washed clean before. And you'll still get a lot of dust.

If there's no easy way to do that, just use pool water on the yard and lower CYA over a few weeks.

 

[picchu55]

No easy way to divert rain into the pool since it's a good bit away from the gutters, and higher than the patio. Whole thing was apparently built to drain rainwater away from the pool. Even if I could, I definitely wouldn't want to this time since it's the first rain on a new roof.

Any value in over-chlorinating today to help compensate for the rainwater? I'm just now getting the water cleared up (it got cloudy while I learned how to use the equipment and while I waited on my test kit), so I don't want the rain to put me right back where I was before.

 

[Richard320]

No easy way to divert rain into the pool since it's a good bit away from the gutters, and higher than the patio. Whole thing was apparently built to drain rainwater away from the pool. Even if I could, I definitely wouldn't want to this time since it's the first rain on a new roof.

Any value in over-chlorinating today to help compensate for the rainwater? I'm just now getting the water cleared up (it got cloudy while I learned how to use the equipment and while I waited on my test kit), so I don't want the rain to put me right back where I was before.

If you're cloudy, it's the beginnings of algae, and you should have chlorine real high to kill it before it gets any worse.

 

[picchu55]

Pretty sure it's the tail end of it. Been battling it for over a week without a proper test kit (hence why I took a sample to Leslie's last week) and have been treating based off their measurements. Wasn't able to do a proper SLAM without the test kit, so I've been going little by little adding bleach at night then vacuuming and brushing all day. Rinse and repeat each day, and things are almost crystal clear.

But your point is still valid. No need to let the FC levels slip for any reason and let the algae come back.