Briefly used bromine, now want my chlorine back

[dlwilliam]

Updating my tests results since May 26, when I started trying to eradicate the very small amount of bromine I added to my chlorine pool in a misguided attempt to go bromine. I have a gunite pool in full sun heated to 88 degrees.

5/26 8/6
Fc .6 1.0
Cc 1.0 0.0
Ph 7.2 8.1
Ta 70 90
Ch 160 210
Cya 80 35

I'm thinking of adding a stabilized puck to my chlorine feeder occassionally to add some CYA and get the pH down a little. The plaster on the pool etched over the winter, so I think my Calcium must have been low. I added some in June and it's been holding CH at 200 or a little higher. Water looks great with no visible algae but I struggle to get FC up. Using 2-3 gallons of liquid chlorine from Walmart each week added to 12k gallons. Thanks.

 

[kellyfair]

Did you drain water? CYA going from 80 to 35 (round up to 40) in a couple of months just doesn’t happen without replacing water. I would not add pucks because you don’t need higher CYA unless you go to SWCG (which we all encourage you to do!) If you are struggling to keep chlorine high enough now, more CYA isn’t going to help.

How often are you adding LC? What happens if you add enough to get to upper lever of target for your CYA of 40, if your testing is right?) Does it drop super quick?

Also, probably want to lower your PH a bit.

 

[kellyfair]

I just re-read your post… your weekly chlorine total might be low. For a 12k gallon pool with 1 FC and CYA OF 40, you need to add a little over a gallon to get to top of your target range of 7-ish. Goal is to keep it around that daily, so when it gets used up you still have enough to protect pool until you get to the next day’s addition. If you drop 3-4ppm daily, that means your next addition will need to be about 3 quarts.

I like to run a bit higher than my target range since I live in hot sunny FL, so if my CYA were 40, I’d be shooting for 8 or 9 everyday.

 

[dlwilliam]

question about liquid chlorine, will I get some residual strength if I finally it to 4 or 5, or does it just come and go? I feel like I'm adding a lot of chlorine at 4 gallons a week. My FC by the week has been all over the place: .6/.4/2.2/2.8/.6/5.6/3.4/1.0

 

[kellyfair]

So, you consume some every day, due to sun, dirt, sunscreen, sweat, etc. How much you use up varies, but as an example, if you start out with 0 and you raise it to 4, you could easily use that 4 in a day. Bringing you back to 0. Not good, and asking for algae. Then there is the issue of CYA. The more you have in your pool, the more chlorine you need to get to an effective level. But if CYA is too low, it doesn’t protect your chlorine enough to keep an effective amount in your pool long enough to fight the nasties. So you shoot for an appropriate CYA for your pool and your exposure. If you are using LC you want 40 or maybe 50, but if you are using a SWCG you want 70 or 80 (SWCGs add little bits of chlorine constantly, instead of a big glug once per day).

Now, if you get your pool up to target or slightly above and you use 4ppm in a day, your daily dose will get you from a minimally acceptable level back up to target or above.

If you don’t try to maintain daily, you are going to use a lot more chlorine than you do now, because you’ll be fighting algae all the time.

 

[JamesW]

Your best bet is to get a SWG.

If you have a variable speed pump and an SWG, you can maintain an adequate chlorine level by running 24/7 because it is is continuously generating.

Even if you have a lot of bromide, it will work as long as you generate at the correct rate, which can be confirmed by doing an OCLT.

If you have a lot of bromide, the level will stay at maybe 3 ppm and when the bromide is gone, the level will rise significantly higher.

Target adding about 4 to 5 ppm chlorine per day and see where the FC levels off.