TA problem

[jeffl1107]

Hello all! I am new here so a quick hello to everyone.
I was a little late getting our pool open this year. Usually have it for people to swim on Memorial Day but not this year.
Anyway, to get it in shape for the season, I did the following. And just so you know, have a 22,500 inground pool with vinyl liner in NJ. Pool was filled from well water but have always had no problems with getting everything in check for the season.
Anyway, this is the second year I have been using items other than from the pool place except for the chlorine shock.
Brought the water to be tested at local pool place.
PH 6.9
TA 0
CYA 18
CH 49
Total & Free Chl 0
I am using a strip test kit.
So, most of everything was not that far off when I opened pool on Saturday. I put in 18lbs.(Two batches of 9lbs. about 6 hrs. apart) of Baking Soda to bring the TA up to par. It did the trick and also brought the PH right were it needed to be because that was not far off. The only thing I had left to adjust was my Hardness. I looked everywhere for the Calcium Chloride but could not find it. I ran across a guy at Ace Hardware that said he uses the regular salt that is used for a in home water softner and has had great success with it. After talking to him at length about it, I finally made the decision to get it. It was a 2 bags of 40lbs. for $11 or $75 for 50lbs. of the calcium chloride from the pool place. Pretty easy decision.
Anyway, I added about 25lbs. last night. Put in about another 20 to 25lbs. early this morning. Let it circulate threw my sand filter for about 3 to 4 hours. Tested again. Everything was right on the money. So I then waited till just about 1 hour ago when there was no direct sunlight. I put in 4 bags of chlorinated shock per the pool places suggestion. It had 78% of chlorine in it. I waited about an hour and went out and tested. Everything looked good except for the TA. The Alkalinity went down considerably. About 6.8 right now. I am trying to figure out what the heck happened. Why would that have decreased so dramatically. Any suggestions appreciated. Thanks

 

[Butterfly]

Everything looked good except for the TA. The Alkalinity went down considerably. About 6.8 right now. I am trying to figure out what the heck happened. Why would that have decreased so dramatically...

Are you talking about the TA or the pH? The baking soda would have little effect on the pH.

You can use the Pool Calculator (link in my sig) to determine the "effects of adding chemicals" to your pool. It is located near the bottom of the calculator.

Welcome to TFP

 

[257WbyMag]

Good advice from Butterfly.

Welcome to TFP!

 

[zea3]

What was the brand of shock? There are some that add extra things to manage TA and pH. Just so I understand, you are using water softener salt instead of calcium increaser? Granted, you have a vinyl liner so your CH target range is 50-300 and you were just about there before adding salt.

 

[dmanb2b]

OK 1st, welcome to TFP

Next...Pool Store test results are seldom correct. IF, TA is truly ZERO, your PH is likely below 5 which is bad. That said, I do not want you to panic, but use this information to question the test results. They guy at the HW store suggested solar salt or calcium chloride based driveway melt? If you bought the regular blue baged solar salt, all you did was add salt to your water as there is no calcium in it (Sodium Chloride).

How are you testing otherwise? You mention your results were spot on...could you share those results with us? This information will only help us assist you better

Zea...caught this...if you have a vinyl liner, CH is basically not meaningful, unless it is too high.

 

[jeffl1107]

Hey guys,
Thanks for the reply and thanks for the welcome to your forum.
Ok,
Butterfly, I was talking about the TA. when i first added the 18lbs. of Baking Soda it brought the TA up to where it had to be, but also brought the PH to a good level. (Also, how much affect does the Baking Soda have on PH? I saw on your calculator that it evidentually does have some kind of affect.)

zea3, yes, I used water softner salt. The Blue Bag. The brand of Shock is Poolife Turbo Shock. It says 78% Calcium Hypochlorite and 22% other ingredients which I cannot find what it is.

dmanb2b, yes, used the salt for water softner. Like I mentioned, I am using a test strip kit like I use every year and it has been good for me. Always had good water clarity and never a problem with algae. It is Smart Test.
Before adding the shock, the strip showed the following.
Alk 80-90
PH 7.4
Hard 150
That is what it showed before I added the 4 bags of shock. After adding the shock, everything showed the same but the Alkalinity, which showed around 40.
Which kind of a test kit would you suggest?

 

[JasonLion]

Salt doesn't contain any calcium. It won't hurt anything, but it also won't raise your CH level. Using Poolife Turbo Shock will raise CH, though only slowly. Of course there is no need to raise the CH level.

Am I following correctly, TA went down from 80 to 40 to 0? Nothing you have described will lower TA like that. If I have that right, it sounds like your TA test results are wrong.

 

[jeffl1107]

Yes, you are following me correctly. TA was 80 before I put the shock in. After I shocked it, I waited 1 hour and then went and tested it. The first test showed between 0 to 40 on the chart. I thought that is odd and then did another test. Same thing. It is showing 0 to 40, in that range on chart.
Which test kit would you suggest that I use for an accurate test?

 

[Butterfly]

Most of us prefer the TF100 from TFTestKits.Net and the Taylor 2006 is also good. There is an article in Pool School comparing test kits.

 

[jeffl1107]

Yeah, I found it after posting that last one. Thanks for your help. I am hoping tomorrow it will read close to ok when I get a better test kit. Not sure what happened today.

 

[jeffl1107]

Have an additional question maybe you can help me with. I looked at your recommended pool chemical page, but being new to this, I am a little confused. What do you suggest to put in the pool in place of the chlorine pucks that the pool place sell. They are very expensive and would like to know an alternative to using them.

 

[JasonLion]

Many people here use household bleach, no fragrance or other additives, to add chlorine to their pool. It is usually a little less expensive than trichlor and easier to control because it isn't constantly lowering the PH.