weird test results from tf100...

[mutex]

I have a pool that was black, 2 bottles of shock later it turned green (a huge improvement!). The pool place told us to keep adding shock, and over a 2 week peroid we added a total of 4 gal bottles of 12% bleach. They also suggested we add chlorine tablets so we added 1 "blue shield slo poke" chlorine tablet last weekend. We bought a cheap pool test kit and saw the ph was at the bottom of the color chart and added blue shield ph increase (looks like its just sodium carbonate) and it later tested at the recommended 7.6.

The pool wasnt getting any better, i searched around and found this forum and ordered a tf100 which we got today. I havent added any chems to the pool in a few days. The last thing was 1/2 a gal of 12% bleach 3 days ago.

I figured the pool would have relatively low chlorine since im alot of what we added was used up, and we didnt add enough to really shock it correctly. I also assumed our CYA would be low since i never added any stabilizer, unless it was included in something else we added.

But the results im getting from the tf100 are weird....I reran all the tests with another water sample just to make sure.

CYA 50
FC 30
CC 2
TC 32

I try to measure the TA...the water turns blue & yellow which is noted may happen with a color shift...but after 40 drops of reagent it still hasnt turned red. Not even faint pink. I run the test again adding the reagents before it turns to yellow (I dont think that'd really make a difference but i tried anyway)...same result. I figure whatever the number is its really really high and not worth wasting more reagent.

I measured the ph/chlorine...the chlorine side turns orange, from high chlorine levels maybe?...and the ph side turns yellow. I thought i had reversed the reagents so I did the test again, then again with the old cheap ph test kit I had...all the same results. Safe to say the pH is really really low.

The water is green, and you can only see about a foot into the water. We cleaned out huge amounts of leaves from the bottom when we started...there was even some things growing in there (yikes!) but we dont find any on the bottom now, but the skimmer fills up with leaves and stuff a few times a day. We've scrubbed the sides to release any stuck material/algae a few times. The pump/filter has been running 24/7 for 2 weeks, backwashing regularly.

So where to start? Raise the pH to a normal level? Any idea why my TA is so high?

 

[duraleigh]

1. Using 20 Mule Team Borax, raise your pH to get to 7.0...no higher.

2. If you use just pool water in the CYA view tube (no R-0013 reagent) does the water alone obscure the dot at any level?

3. Disregard the TA....we'll address it later.

4. What does your water look like? Any solid material still on the bottom of the pool?

 

[mutex]

1. I had to go away for the day, but ill do it get the pH to 7.0 tomorrow using just borox

2. The water doesnt obscure the dot at all with no reagent.

3. Disregard TA for now...easy enough

4. The water looks ok for the 1st foot, then it turns a cloudy green. You cant see anything after that. We got most of the solids out, but its hard to get what you cant see, and i was hoping the visibility would improve so we could see what we needed to pull out. My gf said she'll vacuum the pool today till its not pulling anything else solid out.

So she'll vacuum today, and ill get the pH to 7.0 tomorrow and I'll repost. Thanks so much for your help!

 

[duraleigh]

OK

1. Get that pH up to 7.0.......no higher.

2. Get out all the solids you can....hard to do but an important step.

3. Your CYA is indeed 50ppm so consult the FC/CYA chart and you'll see you need to hold your Chlorine @ 20ppm throughout the shock process.

4. read "The ABC's of Pool Water Chemistry" up in Pool School. Then, read "How to Shock Your Pool" .

5. Follow the "Shock your pool" article precisely and you will end with a crystal clear pool. It'll take patience and some hard work but your water is crystal clear.....you simply have to remove the stuff that's currently obscuring it!!

 

[mutex]

OK, numbers-wise, this seems like im making some progress. We got everything out of the pool (leaves, bugs, corpses etc) and got the ph to 7.0...well as close as to 7.0 as I can read on the color chart between 7.2 and 6.8.

I had noticed the other day the TC dropped down to 17 so i added some bleach. Its at 20 now so ill add more tonight just so im a little higher than required.

So this is what I have now....

FC 20
CC 2
TC 22
pH 7.0
TA 50
CYA 50

That seems better. I was trying to figure out things before with the pool calculator but with the TA missing it was difficult. Im assuming i follow the Shock Your Pool instructions until:
CC is 0.5 or lower;
An overnight FC loss test shows a loss of 1.0 ppm or less;
And the water is clear.

The pool is looking much better too! Its still cloudy and slightly green....but much much better than before! Thank you!

 

[jblizzle]

The concern I have is when you adjusted the pH? When the FC is > 10ppm, the pH test will read artificially high. If you are showing a pH of 7.0 with FC at 20ppm, I am afraid your pH could be well into the 6s ... not good.

I would almost suggest you let the FC drop below 10ppm and adjust the pH to around 7.2ppm then resume the shock process (and don't test anything while shocking besides FC and CC ... it can all wait until you are done.)