Fiberglass pool: chlorine tablets or liquid chlorine exclusively

Jun 29, 2016
6
Burr ridge IL
I have a fiberglass pool and last year I used the chlorine tablets and my water was perfect all summer. I have been told that the tablets are not good for the pool since the 1% waste from them will add up and make things very bad over time (can't empty the pool). I have started using liquid chlorine only but it's a pain. I'm adding half a gallon a day and my fc is nowhere near normal levels since it burns off quickly. Would like to have at least I tablet in the skimmer sock at all times and supplement with liquid chlorine. Bad idea?
 
CJ83, I too am a FB pool owner, and I think there are a few things that we can help you with:
- Regardless of the pool type, proper balance of CYA and FC are key to keeping your pool algae-free and retaining FC throughout the day (Chlorine/CYA Chart link below)
- Depending on the tabs used, each one adds between 7-9 ppm of CYA
- (FYI) Other items (CH, pH, and TA) can also cause some other ill-effects in our FB pools if not maintained properly (i.e. scale)

A couple other things specific to your post:
- I suspect your CYA may need adjusting which is why you can't maintain a proper FC level. Test results will tell for sure.
- We never place tabs in the skimmer - too acidic. Always use a floater or in-line chlorinator if you have one. But yes, bleach and tabs can be used at the same time, just never mixed in the same container.

And just in case someone hasn't told you already, you don't have to run your pump 24/7 (in your sig) unless you have some very unusual/heavy surface debris issues in your area. But for now, post those water results so we can help tell you what's happening.
 
I'm only adding about a fifth of a gallon of liquid (12.5%) a day to maintain my FC level and that's in a 34k gallon pool that came with the house we just bought. I agree that it isn't as easy as using tablets. I have a chlorinator tank so it is tempting.

If if you're adding half a gallon, a full round of tests is in order. Everyone here has been very helpful to me, for sure, and it always starts with a full test report.
 
Ok so I used the taylor drop test kit for everything except for CYA where I used 2 different brands of paper test swabs. I shocked the pool 3 days ago so CC should be good.

Ph 7.4, 280 alkalinity, 200 calcium hardness, CYA 0

I have added 7 pounds of CYA previously, first batch by mixing in bucket dispersing around the pool. This caused some to stay on the floor and it was a pain to dissolve. The next batch I mixed in bucket and added to skimmer directly. Still after all this the CYA did not go up. I'm working on lowering the alkalinity by adding muriatic acid and then letting the Jets aerate the water. BTW I aldo have an auto cover that is always on unless we are in the pool or I apply shock.

- - - Updated - - -

BTW I used the following brand:
Pool Mate 1-2607B Stabilizer and Conditioner for Swimming Pools,
 
CJ, a few updates from the info you provided:
- Yes... definitely try to get more CYA reagent. Everything from this point forward (accurately) hinges on that one test.
- Here at TFP we don't do typical "shocks" like what you would hear at the pool store. We "SLAM" (link below) to resolve algae/cloudiness issues. From the sound of things, you will need to perform a SLAM to resolve your current chemistry dilemma.
- Your last FC of 1.1 confirms something is wrong for it to be that low. You can increase with regular bleach, but if the algae is in there already (I believe so) the SLAM is what is needed. But we need an accurate CYA number first before you can SLAM.
- FYI ... when we add granular stabilizer, we advise to do it this way:
To increase CYA via granular stabilizer, place the required amount as calculated by the Poolmath calculator into a white sock and place in the poolside skimmer basket. For those concerned about suction flow to the pump, suspending the sock near a return jet or from a floating device will also suffice. Best never to allow undissolved granules to rest directly against the pool surface. Squeeze the sock periodically to help it dissipate. Once dissolved, consider your CYA adjusted to that programmed (target) level. CYA test readings should show a rise in 24-48 hours, however some pools may experience a longer delay to fully register. Best to confirm final CYA in about 5-7 days before adding any more stabilizer/conditioner.

The autocover is a good idea to help you retain FC, but make sure to expose the pool daily to let the CC oxidize properly. When you finally go into SLAM mode, you may want to leave it open more. Also, make sure to inspect and/or clean the underside of the cover for algae.

Once you are able to test your own CYA, let us know what it is and we'll be glad to help you some more. BTW - working on that TA is a good plan as well.
 
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