Added 300 oz 12.5% bleach...gone in 24 hours :/

[gdog2004]

Hey guys:
I went on vacation and came back to a algae-ish pool . I thought i added enough chlorine prior to leaving but rain and sun may have dissolved it quicker than expected. FC was at zero when I returned (after 8 days)
The water wasn't green or anything but a decent amount of algae was on the walls of the pool. I brushed down the pool and added 300 oz of 12.5% bleach which should have bought the Chlorine up to around 14 (I had 25-30 CYA). I left the pump running overnight.
I went and did a drop test today and the FC was down to 4. How is this even possible ?

 

[mknauss]

Very. Follow the SLAM Process

 

[Dirk]

The "M" in "SLAM" stands for "Maintain." Just "shocking" a pool with a high dose of chlorine won't do the trick. You have to maintain the correct high level until the algae is gone, and you determine when algae is gone by several tests. It might take a day or two, or it might take longer. It's all part of the SLAM Process that you must now complete. Read the directions carefully, follow them to the letter, and don't cheat, or you'll probably just have to start over and do them all again.

 

[Dirk]

If travel is in your future, you might want to consider an SWG. Not only will you save on chlorination in the long run, once properly adjusted, you can leave it unattended for days, even a couple weeks if you're really dialed in, and come back home to a perfectly, pristine algae-free pool. I could go eight days, no problem. And just think of it: no more lugging chlorine jugs every few days.

 

[gdog2004]

The "M" in "SLAM" stands for "Maintain." Just "shocking" a pool with a high dose of chlorine won't do the trick. You have to maintain the correct high level until the algae is gone, and you determine when algae is gone by several tests. It might take a day or two, or it might take longer. It's all part of the SLAM Process that you must now complete. Read the directions carefully, follow them to the letter, and don't cheat, or you'll probably just have to start over and do them all again.

I get it, I've SLAMMED my pool many times over the years and followed the instructions to a tee.
I have never seen so much chlorine evaporate in such a short period of time. I replenished it with the same amount and the same variables (30 CYA, PH in range) and it dropped 1 or 2 FC levels in a 24 hour period which is more in line with what I have seen in the past.

 

[Dirk]

It could be algae, or it could be the chlorine. Where did you buy it? How long was it sitting around in the store? Or in your garage or yard? Does it have a date code?

If you're using dead chlorine, you might not be losing as much FC as you think, it was never there to begin with.

You can test your FC 30 minutes after you dose to determine if the LC you added really did elevate your FC as expected. After the sun goes down is best for this test. Of course, you have to be algae-free for this test to mean anything. So the OCLT is first. It's kind'a a chicken-and-egg problem. And you might have both things going on: algae in the water that you're shocking with bad chlorine.

Let's see, I think you can combine these tests: do an OCLT, but also test the FC a half hour after adding the proper amount of chlorine. The OCLT FC-start level gets verified by a second FC test, then compare that to the FC in the morning. That way, you're not assuming what you dosed the night before brought the FC up as expected.

And this is another in the plus column for an SWG. Your chlorine is made fresh daily! You never have to think about expired liquid chlorine.

 

[gdog2004]

It could be algae, or it could be the chlorine. Where did you buy it? How long was it sitting around in the store? Or in your garage or yard? Does it have a date code?

If you're using dead chlorine, you might not be losing as much FC as you think, it was never there to begin with.

You can test your FC 30 minutes after you dose to determine if the LC you added really did elevate your FC as expected. After the sun goes down is best for this test. Of course, you have to be algae-free for this test to mean anything. So the OCLT is first. It's kind'a a chicken-and-egg problem. And you might have both things going on: algae in the water that you're shocking with bad chlorine.

Let's see, I think you can combine these tests: do an OCLT, but also test the FC a half hour after adding the proper amount of chlorine. The OCLT FC-start level gets verified by a second FC test, then compare that to the FC in the morning. That way, you're not assuming what you dosed the night before brought the FC up as expected.

And this is another in the plus column for an SWG. Your chlorine is made fresh daily! You never have to think about expired liquid chlorine.

Yeah, I didn't look at the date on the Chlorine...not did I test on the day I put it in (later that day). I suspect it was bad chlorine. My pool was pretty clear overall, just algae on the walls. Right now, I would say its Dang close to algae free and crystal clear.