Where is the chlorine going??

[Paigemar]

I'm at a loss here, as I have dumped huge amounts of granular chlorine (power powder, the kind without stabilizer) in my pool yesterday, tested the water an hour later and the chlorine was at ZERO. This morning I took a water sample to the pool store and got this:
FAC 0
pH 7.4
Alk 80
TDS 1200
CYA. 50
Phos 0
Calcium hardness 280

I've owned this pool for three years, but the pool itself is about 10 years old. It's never held chlorine as long as I've been maintaining it, and I can't figure it out. I do live where it's hot and sunny, but geez!
I've heard about using regular liquid bleach, is this better?. The lady at the pool store tried to sell me something called ' The Purge', which is a big bottle with an enzyme that supposedly clears your plumbing like Drano, because organic matter could be in the pipes eating the chlorine. It sounded like sales junk to me, so I didn't buy it.

Any thoughts??. Thanks for any advice..

Paigemar

17,500 gal fiberglass in ground pool
DE filter, cleaned and grids replaced 1 month ago
Inline chlorinator kept full of tabs

 

[jblizzle]

Welcome to TFP!!!

A few pieces of advice:
1. Stop going to the pool store and trusting their testing ... it is notoriously inaccurate and seems to often just drive sales
2. Invest in one of the Recommended Test Kits to take control of your pool
3. Post up a full set of reliable test results and lets see what we need to do

 

[Texas Splash]

Hello and welcome to TFP! Your #1 priority right now needs to be the right test kit. Either the TF-100 (link below) or Taylor K-2006C will work, but you need one of those and to stay far away from the pool store and their magic potions. I have the TF-100 and it's the best thing I've done fro my pool. Start there and post a full set of test results and we can help. Nice to have you with us.

 

[Paigemar]

Thanks for the responses! I do have a Leslie's/Taylor test kit, says Deluxe Poolcare DPD test kit. I actually went to the store looking for this FSA test, and couldn't find anything. Is this only available online? I will probably order the TF-100 kit. In the meantime, will these numbers get me anywhere? I tested tonight with the home test kit I've got here. I know, patience is not my virtue!

FC- 1
TC- 2
CC- 1
pH- 7.2
TA- 70

 

[jblizzle]

You need the FAS-DPD chlorine test. If yours is the K-2005, then you can add the FAS-DPD test and have the equivalent to the K-2006.

tftestkits.net sells just the FAS-DPD chlorine test ... it is very rare to find it locally.

Need to know CYA, that determines your required FC level, see [FC/CYA][/FC/CYA].

 

[Paigemar]

Well, my test kit came in the mail today!. I'm currently just starting to SLAM the pool to get rid of the algae that has grown while waiting for the test kit, and to get a good start to maintaining the chemicals myself. Here are the numbers, which I did today before any chlorine was added:

CYA 50
CC. 0.5
pH 7.5
TA. 120
Ca 575. ( did this one twice)
TC. 0
Borates 30

After adding a ton of chlorine, the level is currently at 20, and I'll test that again in a couple of hours to see where it goes.

I know my calcium is super high and I admit I haven't read up on what to do yet. Is this something I deal with later after the SLAM is complete or is there anything I need to address now?

 

[jblizzle]

To lower the CH you have to replace water. Yours is not terribly high. Just have to keep your pH a little lower.

 

[AimeeH]

Hi paigemar and welcome to TFP

Congrats on a good test kit. One thing I'm going to mention regarding your SLAM process, is that you need to switch to liquid chlorine. All dry chlorine is stabilized either by CYA or by calcium. This "could" be partly the cause of your high calcium hardness level but I didn't look that product up. Dichlor and trichlor are stabilized by CYA and cal-hypo (calcium hypochlorite) is stabilized by calcium.

 

[chiefwej]

Your calcium is high because you are adding calcium hypochlorite. That powdered chlorine is 1/3 calcium. If you use any solid or powder form of chlorine , it adds something you don't want or need. Either CYA or calcium. In either case it will build up and cause you to have to drain the pool to get rid of it.

 

[Paigemar]

So it looks like my SLAM is complete, the pool is crystal clear, FC held at 10.5 overnight, and CC tests at 0.5
I am thankful for this site, so helpful!
Now to maintain...
This morning's test at 10.5 FC is now 8.5 this evening after a full sunny July day. Would I test over a period of a few days to get an average daily loss or would it be pretty consistent?. I need to find the proper dose of chlorine to maintain the level. The bleach I used for slamming is from good ole HEB, it's a 96 oz jug for a dollar. Seemed like a good deal to me, but there is no percentage concentration listed on the bottle. What concentration do I assume?

 

[jblizzle]

If it does not say the %, then it is likely weak <3% How did you calculate the correct asking to add for the SLAM process without putting in the bleach strength into PoolMath?

 

[Paigemar]

The pool math calc has the 'default' strength at 6, so I left it at that level, unaware that there was a lower strength out there. Looking back, I did usually end up adding more bleach to the pool than what the calculator said in order to get my FC level to 20..

 

[beemer]

The 121oz. generic HEB brand I buy is 8.25% for $2.94. Same price & % as the no name brand at Walmart as well. It's works great. Just check the Julian dates. We must have several TFPers in the area as they sell massive amounts of bleach all the time, but aren't great stockers as we often find all the older dates pushed to the back. So when we all make a run for 6+ bottles it's slim pickins left.