Can't raise the FC

Jun 5, 2011
5
Raleigh, NC
Hello everyone,
Found this forum because all the links to the questions I 'googled' seemed to point back to you! :-D So, as the title states, having a bit of trouble with the FC. Here is my progress.

Second year of owning a pool.. so very much still a newb. Pool is a 25k gallon with vinyl liner. I decided to convert to a SWCG this year and have everything installed and 'seems' to be working fine (powers on, reads salt level and was originally on 100% output upon pool opening).

After a few days of running the SWCG, I was still getting a zero FC reading on the test strips. (I know now.. test strips are the worst.. as I said, I am still a newb and they seemed to work ok last year.) Will be picking up a k-2006 from Leslies soon (maybe today). Was reading around and saw people for and against the 'myth' of chlorine lock. Put bleach in (3 of the 182oz bleaches) to attempt to raise FC. Waited a day, still showed no FC. Thought maybe my strips were bad, took a sample in to Leslies for testing.

Results were:
FC: 0
TAC: 1 ppm
Salt: 4500ppm
CH: 200
CYA: 50ppm
TA: 50ppm (Leslie's paperwork shows this as Low)
pH: 6.8 (also Low)
no metals showing (Copper, Iron)
Pho: 200 (shows as High)

So I was instructed to use 3lbs 8 oz of ChlorBrite and 4lbs of Soda Ash. So I did that. Soda Ash in first and then about 6 hours later, the Chlor Brite. Ran it for the night and checked the next day. No FC still. Turned the SWCG back on and ran it for a couple of days. Still no FC.

So then I head over to the Pool Calculator. If I look at the 'Chlorine/CYA Chart', it says for a CYA of 70, it's 28 ppm for Shock FC. Plug that in to the calc and it gives me 3.2 jugs of 128oz of bleach. (HERE IS MY MISTAKE yesterday). I somehow put in 10,000 gallons in to the calculator instead of 25k. So last night I put in 4 jugs of 128oz of bleach.

I read this morning and look at my open page and realize it had 10k and I up it to 25k in the calc. It says it was supposed to be 8 jugs at 128oz each. So I was 4 jugs short last night.

So my question is.. should that be my next thing to do? To get 4 more jugs as quickly as possible? I put those 4 in last night so the sun didn't eat up the bleach/chlorine during the day.. as its very sunny and very hot (90s) right now around mid-day.

So what next? Any help/ideas??

Thanks!!
 
Welcome to TFP. I think that you have something in your water that is consuming your FC and you need to shock your pool until you hodl you FC overnight, you have 0.5 or less CC, and your water clears. Shock with bleach and turn your SWCG off. It can't keep up[ anyway.

Please visit www.tftestkits.net and get a TF-100 kit. Not have a good test kit is causing you to spin your wheels. Leslie's won't have a K-2006 probably and the TF-100 is a superior kit anyway.
 
Thanks! So should I start with another 4 jugs of the 128oz bleach? As well as.. is there a local place to get the TF-100? Or do I need to order it through the site you mention? And the SWCG has been off for the last 2 days.. I figured it wasn't doing much to help anyways since it should be a small increase generator.. not a shocker. Forgot to put that in the post though. Thanks again.
 
You almost certainly need to raise both the TA and PH some more at this point.

I'd add eight jugs of bleach right now. Chlorine gets consumed quickly when you are fighting algae. The four jugs from yesterday are probably gone already.

The best thing would be to order a TF100 from their web site, and pick up a cheap chlorine/ph test locally to use until it arrives.
 
Ok, thanks.. I also forgot to mention my algae treatment.. but I promise.. that is the last of what I have forgotten :) I know its hard to troubleshoot when you don't have all the facts. After I got back from Leslie's and put in the ChlorBrite and Soda Ash, 2 days later I put in about 1.3 bottles of 50% algaecide. It looked a tad green (just a hint really) and the bottle said to use a little more than a bottle for a 25k pool. So i think it is algae free. This was about 3 days ago. The pool is crystal clear and blue at the this point. I will head to Walmart and pick up more bleach. I will also increase the pH today too.
 
ChlorBrite is Dichlor where for every 10 ppm Free Chlorine (FC) it also increases Cyanuric Acid (CYA) by 9 ppm. I certainly hope you didn't use a lot of it because your CYA was already at 50 ppm and you didn't want to raise it further. You really need to decide whether you are going to follow the often inaccurate advice from the pool store or the accurate advice on this forum.
 
chem geek said:
ChlorBrite is Dichlor where for every 10 ppm Free Chlorine (FC) it also increases Cyanuric Acid (CYA) by 9 ppm. I certainly hope you didn't use a lot of it because your CYA was already at 50 ppm and you didn't want to raise it further. You really need to decide whether you are going to follow the often inaccurate advice from the pool store or the accurate advice on this forum.

Yeah, I am a forum junkie true and true.. DIY til I die (though cars and android devices mostly - til now when I get to play in the pool for the summer).. unfortunately I didn't find this forum until after. Alas, I am here now.. like it or not. :wink: I put in the 8 jugs of bleach earlier.. and will check then put in the pH increaser in just a few minutes. As of 5pm tonight.. I am now well in to the FC purple. Will check it tomorrow though of course to see if it held through the first 24 hours and reply back with the results.
 
2 days down and the Chlorine is doing great! Thanks for the great help, guys!

Quick threadjack to a different topic, though at the moment I haven't searched yet so the info may be in there.. just wondering how a 2-speed (Emerson EB982 which runs at 1hp and 1/6th HP) pump affects a SWCG output? I usually leave the pump on 24hrs/day on the low HP setting. Are there any extrapolations for how much more output % should be added due to the reduced throughput when the pump is on low? Since the SWCG is new to me, I don't have the experience yet for how my geographic area will affect the output needs of the SWCG.. much less what a reduced pump output would do to it. Figure it will likely be a 'Different for everyone, just monitor your chlorine more often' type response, but thought I'd ask.

Thanks.
 
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