New pool owner. Cya level over 100. No free chlorine detected....help

Thank you so much for all the great info I've been reading so far about how to manage my pool. I have just tried to start caring for it using your techniques. I have my taylor kit on the way but it won't arrive until Thursday. In the meantime, I am relying on Leslie's pool store for my testing. I have a fiberglass pool, 8 k gal, paper filter cartridge.
On Saturday here were the results:

Fc 0
Tc 0
Cya 100
TA 75
Ph 7.7
Phos 1000

They told me to add 2#13oz alk up (I know it's baking soda but I bought it out of convenience) then do 1# chlor brite dichlor 4 hrs later. I immediately put in the baking soda but waited on the chlor brite.

After reading your wonderful site, I knew the cya was a problem and further investigation about the di chor made me suspicious of using it. So I bought regular bleach at my grocery store and added it the next morning directly to the skimmer. I used about 1/2 gal. Since I didn't know the strength of it. Soon the pool took on a greenish glow. So I thought algae was starting...About 8 hours later I added a gal more of the bleach. Then the pool turned more green. My lousy test strips still showed no FC. So last nite, I added the chlor brite which cleared up the green. But my test strips still show no FC. I'm going to go the Leslie's again to test the water but I don think I trust them. Can you please advise me? I still have an association with a local pool service company who can come out with a phone call. Thank you so much.

Lisa
Frazzled new pool owner

While you are waiting on your kit, go to Walmart and see if they have the HTH 6-Way drops-based kit. (No test strips.) If not, get a cheap OTO/Phenol Red kit (yellow and red drops). Also, get a bunch of jugs of Walmart's generic 8.25% bleach and a bottle of distilled water.

If you can find the 6-Way kit, it has a CYA test but it can't read over 100. (Neither can your pool store's test. 100 is the maximum reading that can be distinguished. So, your CYA may actually be a lot higher than that.) Take a cup of pool water and mix it with a cup of the distilled water and then use that for the CYA test but multiply your result by 2. Report back with that reading.

In the meantime, add 3 of the 121-oz jugs of bleach. With a high CYA , it is going to take high chlorine levels to kill the algae. Don't use any more of the Dichlor since your CYA is already too high and that will make it go even higher.

Report back with what kind of test kit you buy and with new numbers including the CYA level if you are able.

Hope this helps.

EDIT --- Rereading your post after I answered. I have a question that you should answer before you add that big dose of bleach in there.
1) Was your pool green at all before you added the chlorine?
2) Was your pool filled from a well?
3) What does the water look like now?

If the answer to question 2 is YES, then hold off adding the large dose of bleach.

. . . membership upgraded.

I also suspect metals in the water -- clean your cartridge (or at least look at it) and see what color the goo on the cartridge is.

Thank you for the great information. Good news...the Taylor kit arrived and I was able to test myself. So here are the results:

FC 0
Ph 7.8
TA 180
Cya 160 (maybe...it was hard to discern)

I added the 3 jugs of Walmart bleach 121oz size this evening. I will check everything again in the morning.

Answering your additional questions:
1. Pool was not green before adding the bleach over the weekend
2. Not well water
3. Water still looked clear and bluish before I added the 3 jugs this evening


I didn't mention that it is an established pool which has been serviced by a local pool company for several years including last summer when we first moved in. I wanted to give caring for it ourselves a try since I live with 3 teenagers. We also added a solar hearing system to it..wow amazing! Got to 85 degrees in a few days and now stays there.

Thank you PoolDoc...I don't know how to open the filter or backwash, etc but I will learn tomorrow when the pool service company comes. I suspect they never paid any attention to cya levels as previous owner had pool drained every spring for cleaning. I'm hearing they are lucky it never broke
in two or cracked:)

Lisa
Less frazzled new pool owner

I have seen pools look green with very high TA -- though I've never been able to determine if that was cause or coincidence. I've also seen pools turn green with iron.

1. Lower your pH to near 7.0 => http://pool9.net/ma/

2. Watch the Taylor videos, so you can be sure you are doing the tests correctly:

http://pool9.net/tk-guide/
http://pool9.net/tk-interfere/

3. Test and report your CH (calcium) level.

4. Complete the pool info form:

http://pool9.net/pf-pool-form/

It isn't possible to get a CYA reading of 160 with the K2006 kit. 100 is the highest number on the scale.......

Hi Watermom and PoolDoc,

Thank you for your help. I watched the Taylor demos and filled out the pool form.

Watermom, I did a you suggested and got a cya reading of 80 which I multiplied by 2 to get the 160 I reported to you:). I'm not sure it's that high though. I had the pool company here this afternoon to show me how to work the pump, chlorination, etc. They tested too and got a cya reading under 100 but they don't always do that test so I'm not convinced that their number is correct. They also added some muratic acid and showed me how to siphon off water if I choose to do that. They had a FC reading of 5+ and TA of 150 approx. as they hadn't written them down. I will test again tomorrow and report all those numbers. The pool looks blue and clear but smells like chlorine a bit. No one is trying to swim so we can see how long the FC holds. Thank you again so much.

Gotcha. I didn't realize that your CYA reading was from dilution. The fact that they got an FC reading of 5+ shows that your kit is better than whatever they are testing with. 5+ on a test kit that only goes to 5 means that it could be 5 or any number higher than that.

When you post your numbers tomorrow, post FC and CC in addition to pH and TA. No need to run the CYA test again.

Thank you. Here is what I got yesterday:

FC: 8
CC: .5
PH 7.4
Ch 270

This chlorine ratio seems out of balance. What do you recommend?

What is your TA reading? How does your water look?

You are at the minimum chlorine level for your CYA. Take a look at this chart for more about the relationship between CYA and needed chlorine levels: http://pool9.net/cl-cya/ Go ahead and add some bleach now so your chlorine doesn't dip any lower through the day.

Her TA was 180 a few days ago.

Composite:

TA = 180
CH = 270
CYA = 160

Given a CYA=160, as long as your pool is algae free, you need to keep your FC between 8 and 16 ppm. Don't worry about CC, so long as it's only 1 drop of FAS (0.5 ppm with the 10 ml sample size).

So, to respond to your question, your chlorine is fine, except a bit low.

Given your high TA & moderate CH, you need to lower your TA a bit. If you would lower the pH to 7.4 or so, and retest TA to confirm. To lower, see http://pool9.net/ma/

I looked at your data, and recalculated your volume as 6,300 based on the dimensions you provided. If the depth measurements were pool depth, rather than water depth, the actual volume is even less.

Thank you, Watermom. So I added another gallon of Walmart 8% bleach early this morning and my pool service added some acid last week.

Here are my numbers:
FC 11.5
CC .5
Ph 8+
TA 160
CH 52

I looked at the best guess chart but don't understand. For my high cya number, should I be aiming for FC of 8 to 15? What does the shock column mean? I need to have my pool swimable by the weekend. Would you advise me to drain some of the water?

Thank you so much.

Thank you, PoolDoc. I didn't see this reply before posting mine. I will lower the ph. There is not and hasn't ever been any algae as far as I know. The pool is approx 8000 gal according to my pool service company. I did not measure the depth and length, I just estimated. I will get an actual measurement and update it.

It doesn't sound like you are concerned about my high cya number. I understand that having a high cya means keeping lots of chlorine in the pool. I'd like to have my pool water be as healthy as possible for my kids to swim in. Wouldn't using less chlorine achieve that? What do you recommend? Thank you.

It is up to you. You can do a partial drain and refill if you want but don't totally drain it. OR, just keep the CYA at 60 and run the higher chlorine levels per the chart. It is fine to do so and your kids can certainly swim with no problems.

CYA and chlorine combine in such a way that, the higher the CYA, the less % of the chlorine that is active. In a very important sense, in a pool with 1 ppm FC at CYA=20 ppm there is the same amount of ACTIVE chlorine as another pool with 5 ppm FC and CYA=100 ppm!

The studies of health risks possibly originating from chlorine in pools, are studies of INDOOR COMMERCIAL pools. Compared to outdoor pools, indoor pools have very poor ventilation. Commercial pools have MUCH higher swimmer loads then home pools. And, perhaps most important, indoor pools don't have the high energy oxidation processes that occur when solar UV photolyses pool chlorine. This process rapidly break down the noxious chlorine + people goo compounds which form, as chlorine tries to clean up the mess people leave behind!

As far as I can find, there is NO data suggesting that swimming in OUTDOOR pools with FC=20, or even 50 ppm. In fact, dermatologists have for years been treating various sensitive skin conditions, in both adults and children, with "bleach baths" where the chlorine level is 50+ ppm, and there is NOT stabilizer.

All that to say, your kids will be fine, as W-M has already told you!

Thank you Watermom and PoolDoc. That is good news that the kids will be fine...me too! I will keep the water in the pool for now but I can see I'm going to be adding lots of bleach to keep FC at 8+.

I really appreciate your time and effort in helping me and others who are overwhelmed with this process. The test kit you recommended is awesome. I think I'll be able to keep maintaining my pool for the most part and only call in the big guns (pool service company) when major things need to be done like opening the filter...yikes!

So grateful...Lisa

Glad we could help. If you have further questions, we'll be here! :)