Can't Keep FC in the Pool

Apr 25, 2018
Test Results:

  • FC:2
  • CC: 0 for now this has been fluctuating
  • PH: 7.0
  • TA: 130
  • CH:50 (vinyl though)
  • CYA: 40 - I'm a noob to CYA tests, so i think this is accurate.
  • BOR:0

I'm starting to get really frustrated with my FC levels. I want to provide a little context to these test results and my situation, so maybe someone can help me understand or point me in the right direction as to what I am doing wrong. I'm fairly new to all this, but I have been using(more like wearing out) my TF-100, and adding bleach.

Pulled the cover off about 10 days ago, looked fairly normal to me, this is my 3rd time opening the pool, I think. Water was mostly clear, but some dirt and debris on the bottom, once I put the filter on, it kicked out a bunch of darker water, and once everything started mixing up, it was fairly dark and cloudy, not like a pond though. My experience previously was it would take about 10 days or so to get cleaned up when I was using the old tri-chlor and powder shock method.

Nothing really seemed out of the ordinary.

However, the pool is a Chlorine Monster, just murdering FC. I only started doing the FAS-DPD FC/CC test maybe 4 days ago. I understand this was a mistake, and have learned this lesson, as my CC has been fluctuating between 2-5 range.

When I first pulled the cover off CYA was 0. I didn't receive the Cyanuric Acid until last Thursday. I knew this was a problem since we went from basically almost freezing temps to blazing hot 90 degree weather for a few days during this stretch, and with a CYA of 0 my FC had no chance.

Fine, so received my CYA on Thursday and ran into my next hard-knocks lesson of getting this stuff dissolved. Long Story Short i ended-up doing the sock method suspended in front of return and also turning on my heater since it just wasnt happening at 55 degree pool temp. This worked. I did about 2/3 of my calculated total one day (massaging the heck out of it to dissolve) and then enough the next day to bring me about 10% of the total calculated. Even though people said to wait for testing, i'm fairly certain its dissolved since I manually massaged the CYA and got my temp up quickly, and it's reading about 40.

Note: I've been learning to add chemicals in stages, for one I find pool math to be somewhat inaccurate in cases, and when you need to move the needle a lot, it can be really inaccurate but that's kind of the nature of things. Also I suspect my pool is a bit less than 25K. Every pool volume calc out there tells me it's about 25K but mine has a giant safety ledge around the entire deep-end and the '8" foot deep-end section' is really only a small area, so I tend to go fairly short on chemicals.

Now throughout all this learning process and my pool has been behaving normally. Been running the filter 24X7, back-washing when necessary, running the bot several times a day, and its slowly clearing up every day. It's almost 100% clear at this point, still a little cloudy in the deep-end, I can't clearly see to the bottom. Had been trying to keep my FC at targets throughout, until I switched to SLAMing a few days ago

I can't seem to keep FC in the pool, it's driving me mad. When I started doing the FAS-DPD and seeing my CC fluctuating I knew 'something was going on' and started to SLAM. I'm putting in insane amounts of Bleach every day, I'm running out to the store for Bleach twice a day. It's getting to the point where I am running out of places to get it, I've cleaned out a bunch of stores(I get some pretty strange looks). Every time I test it goes back down to the 2-4 PPM range.


This is what I am planning on doing now. I am going to put more effort into SLAMing my pool. What I mean is not just randomly dump bleach in the pool. I bought 6 Gs of 8.25 from HD last night and 20Gs of high-concentrate 10% pool chlorine from Wally World.

Last night before I went to bed(FC=3,m CC = 3.5), I dropped 3Gs of 10% and 2Gs of 8.25%, this should have brought my FC up to somewhere around 19ppm. I knew this was over-kill but wanted to make sure it was above SLAM level for the night. Woke-up this morning and FC was 2. I dropped another 3Gs of 10% and 1 more of 8.25%,I'm about to go test again. However my FC was 0, which seemed promising.

Based on previous posts I have gone through, it seems my CYA may have converted to Ammonia, which makes sense since I clearly don't have an algae problem, so I'm hoping if I really pay-close attention to the levels and keep it at SLAM levels I can finally knock this out today.

Anyways that's my story, and this is my plan. Please let me know if you you think this is a good idea and if I may have missed something

2 things I forgot to mention:

My PH is a bit low, I have been slowly adding about 1.5 lbs at a time, and waiting a good 8 hours to re-test and re-add, I don't want to overshoot it.

I think MY TA is wrong, it seems way too high. I need to re-test. I read somewhere in a similar thread about high TA that I should try wiping the tip with a damp paper-towel so that it removes the static charge, this may be casuing smaller droplets which will artificially increase the TA count.

Ok i'm done talking - Thanks


tested after SLAM this morning, FC = 17.5 and CC = 0. Also PH is up to 7.2, but not sure how much I trust that with FC being so high.
Last edited:


Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
Franklin, NC
It's simple - follow the instructions to the letter.

Test and adjust FC back to shock level.
Brush the pool
Stop for an adult beverage