confusing test results

lsasso

New member
Apr 19, 2009
3
Kingston, NY
My pool is less than 1 year old and I'm confused about the test results that I just got. I opened my pool a week ago and have been running it on "low" since. I did a HTH 6 way test strip when I opened it and everything was fine. I have an automatic chlorinator that uses trichlor tabs.
I just retested it with the strips and got: th-200, fc-5, ph-7.5, ta-240, cya-3- to 50. I then retested it with a HTH 6 way test kit with all of the drops, etc. Results: ph-7.2, cya-70-, ta-130, I couldn't interpret cl since it turned red when I added the OTO drops instead of yellow. For the th test-another confusing result- it turned yellow from the hardness indicator drops instead of red. What does this mean? Do I have a problem?
I added about 6 to 8 inches of community well water before I opened the pool. The water has been alkaline and very hard in the past.
What do I need to do to maintain my water? It's perfectly clear now, but I guess that I'm supposed to add shock to it weekly. How much? Thanks.
 

frustratedpoolmom

TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
12,177
SWSuburban Chicago, IL
No one should have to shock weekly :)

Start by reading Pool School...

Tomorrow go to the Pool Store and have them test the water for you, then you should order or your own test kit (we recommend 2).
Trust the drop kits over strips, any day...

But I'm wondering if you maybe did a testing error on the OTO and TH test.
Did you shock recently? Is the OTO Red or a darkish orange/brown?

The pool store should be able to narrow things down.

So, how does your water look now?
 

lsasso

New member
Apr 19, 2009
3
Kingston, NY
The water is perfectly clear. I'm sure that I didn't mis up the 2 drop bottles. I checked carefully after i got the confusing results. The OTO is light yellow.I'll go to the pool store on Thursday-I'm off to the Zoo with the 3rd graders tomorrow.
 

PaulR

LifeTime Supporter
Jan 11, 2009
1,966
Cupertino, CA
If you're sure you put the yellow drops in for the OTO test, and the sample turned red, that means your chlorine is ridiculously high. (It goes yellow/orange/red/brown as FC goes up; but nobody makes a color chart that tells you what those colors mean, other than "wicked high.")

High chlorine levels can also cause the other tests to turn unusual colors.
--paulr
 

lsasso

New member
Apr 19, 2009
3
Kingston, NY
I made it to the pool store to have my water tested yesterday. They found:
saturaion index:-0.29, Corrosive
total dissolved solids:0, OK
free chlorine:3.1, High
total chlorine:3.1, High
combined chlorine:0.0, OK
pH:7.3,OK
Cyanuric acid:9, Low
copper:0.0, OK
iron:0.0,OK
total alkalinity:119
adjusted total alkalinity:119, OK
calcium hardness:124,Low

They didn't say to do anything about the saturation index and said to add 15 lbs. of calcium booster ($43 for 20 lb. container) into skimmer 1/2 at a time with 2 hours of filter running time between the 2 doses. Then, add 4 lbs. of stabilizer into skimmer.
Can't I just use the deicer calcium chloride that I already have to use in the moisture control containers in my boat? My husband said that he's never heard of adding calcium chloride to a pool-but then again, he's never had a pool AND I maintain the pool! The pool store never explained why my fc test gave a red color norwhy the total hardness test turned yellow. They said that I should get a new test kit.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,880
Silver Spring, MD
Red when you add the OTO drops, which normally turn the sample yellow, means your FC level is very high, 20+. Having TA or CH turn yellow also indicated that the FC level is very high.

With CYA relatively low, it should only be one or two sunny days until your FC level is down to something more reasonable.

There is no need to add calcium to an above ground pool. The only issue with calcium that might come up in a vinyl liner pool is if the calcium level was too high, which yours isn't.

Getting a better test kit is an excellent idea. A kit like the TF-100 from TFTestKits.net or the Taylor K-2006 would allow you to find out exactly what the FC level really was. A top quality test kit will also more than pay for it's self in the long run through reduced chemical usage and avoided problems.

Measure the chlorine and PH levels again today with the WalMart kit and tell us what you get. And don't add any more chlorine until the OTO test shows a more normal yellow color.

The only real open issue is what your CYA level is. When you did the CYA test you said 3 to 50, do you mean 30 to 50? Can you describe what you saw in the CYA view tube?
 

Nelsonesteves

Member
Jul 24, 2015
9
Cerritos/ca
Red when you add the OTO drops, which normally turn the sample yellow, means your FC level is very high, 20+. Having TA or CH turn yellow also indicated that the FC level is very high.

With CYA relatively low, it should only be one or two sunny days until your FC level is down to something more reasonable.

There is no need to add calcium to an above ground pool. The only issue with calcium that might come up in a vinyl liner pool is if the calcium level was too high, which yours isn't.

Getting a better test kit is an excellent idea. A kit like the TF-100 from TFTestKits.net or the Taylor K-2006 would allow you to find out exactly what the FC level really was. A top quality test kit will also more than pay for it's self in the long run through reduced chemical usage and avoided problems.

Measure the chlorine and PH levels again today with the WalMart kit and tell us what you get. And don't add any more chlorine until the OTO test shows a more normal yellow color.

The only real open issue is what your CYA level is. When you did the CYA test you said 3 to 50, do you mean 30 to 50? Can you describe what you saw in the CYA view tube?
I think I may be having a similar issue with my OTO (waiting for my TFT fas/dpd test to come in). When I mix the sample it get a nice bright yellow which to me looks like 2-3 ppm but if I add more chlorine and test within 1-2 hrs it's the same color and not the orange color that you would get from 5ppm.

Could it be my FC is too high and the OTO doesn't pick it out?
CYA is approx. 30-50 but basing that on my aquacheck sense I'm waiting on my CYA tester as well.
 

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