Adding a high dose of bleach clouded pool

Jump to latest Follow Reply
S

skillset

0
Gold Supporter
LifeTime Supporter
May 3, 2007
117
Central NJ
Hi gang,

I'm ready to close the pool this Friday morning. This evening, I added 4 jugs of bleach to get the pool to a high Cl state. For my pool, it should have raised about +36ppm. The pool had 5ppm Cl in it prior to adding the bleach and the water clarity was very clear. I'd been having some issues with either pollen or yellow algae the last few weeks - water was clear, but some round brown dirt-like substance was appearing daily but would disintegrate upon swimming. Water remained crystal clear the last few weeks of the season as it was this evening. I test Cl every night and add accordingly to Best guess chart.

Well, after I added the 4 jugs, the water turned cloudy - you could see plumes of clouds rising from the bottom of the pool! I was shocked that just by adding bleach, this occurred. I'm a long time BBB user and this was the first time adding bleach to very clear water caused such a reaction.

I didn't test Ph or Alk today, but last time I did check was over the weekend, the Ph was 7.2 and the Alk was 80. Had to add about a lb of baking soda to get to the 80. Haven't tested the CYA in a few weeks as the pool was holding at 50ppm most of the summer with checks about once a month.

I checked the bleach containers to see if I had purchased the wrong bleach - but it was plain Clorox.

I'm perplexed - and also nervous that I'm closing shortly and the pool now has an issue which I never expected.

I will have the pump run continuously and got out the Slimebag.

Any ideas of what could be the issue? Could the bleach have been contaminated? The pool light in the deep end can't even light the shallow end it is so cloudy.

In looking over some other posts:

http://www.troublefreepool.com/threads/66154-Bleach-turns-into-a-cloud-when-adding-to-pool-water
http://www.troublefreepool.com/threads/22698-Pool-got-cloudy-after-adding-bleach

I wonder if this could have been caused by Calcium in the water per the second post? I did add Calcium, probably 2 months ago, can't remember how much was in the pool, I think it was around 150 or 200. The only other thing in the water might have been some Metal Magic - probably added maybe 3 weeks ago. So only thing that went into the water this season was bleach, baking soda, CYA, Calcium, and Metal Magic - with the usual decent results.

Marc
 
Last edited:
Haven't tested cya in about 2 weeks. Last time was 50. As stated, been keeping at 50 all summer. I only use bleach so when needed, I add cya.

Normally when closing the pool, I add 4 jugs the morning of close. I'm closing on Friday so added a bit early. Again, never had this kind of reaction! Pump pressure up a full lb in the last 90 minutes. Very strange. Pool was backwashed for the second time all season last weekend. It usually takes me weeks to get a lb rise!

I just saw this post which had a similar situation and pool readings as me:
http://www.troublefreepool.com/threads/1631-Problems-after-adding-calcium

And I wonder if the calcium in the water did react with the high dose of bleach?
 
So you just arbitrarily add that much chlorine regardless of the fact that it is way over the shock level recommended in the closing articles in Pool School?

I thought you said the calcium had not been added for months?
 
Yep - Calcium was not added recently - about 2 months ago.

You know, I never thought about the Cl level. I know there's a lot of different ways people close pools. I've been very successful adding the 4 jugs each close, along with Polyquat 60, and never having an issue upon opening. I never have any Cl left in my water at opening but never had algae either. I know the pool temp is supposed to be colder, but I swim until "the last minute" with the temp in the mid 80's, so when I close the temp is in the high 60's. So, I've added extra Cl for insurance the past few years, but perhaps that's been overkill.

Anyway, after 8 hours later, the pool has cleared a lot, maybe 60% there, so hopefully, when I get home from work later on today, this situation will be a short-lived distant memory. No additional pump pressure rise overnight. Still, a bit baffling to me...
 
Update- pool completely cleared up. Not sure what happened, but guess I'll chalk it up to a reaction between high Cl and existing Calcium in the water. Amazing how the pool can go from clear to badly cloudy back to clear in less than 24 hours. First for me.
 
I've never seen my pool do that. But I have a fountain to which I add chlorine to prevent algae. It has done that in a matter of hours.
 
Adding a large amount of chlorine has the pH rise significantly. That can then cloud the pool with calcium carbonate being way over-saturated. There is no mystery here. Even if your pH started at 7.2, TA at 80 ppm, CYA at 50 ppm, and CH at 200 ppm which has a -0.56 saturation index at 80ºF, adding 20 ppm FC of hypochlorite would have the pH rise to 8.07 and the saturation index to +0.33 which still shouldn't cloud, but adding 30 ppm FC would get you to 8.54 pH and a saturation index of +0.79 which could show cloudiness. Adding 40 ppm FC would raise the pH to 8.74 and the saturation index to +0.97.

4 gallons of 12.5% chlorinating liquid in 10,000 gallons would be 50 ppm FC raising the pH to 8.87 and the saturation index to +1.08.
 
Richard - thanks! I'm guessing over 1 on the index means definite cloudiness? The 4 jugs of reg Clorox (121 oz) would have added about 32 to the already 5, so pool was probably about 37 last night so closer to your +0.97 on the sat index. I haven't tested the pool today for ph or Cl but will tomorrow when it's daytime and I can see. Is the only way that the cloudiness goes away is because of a ph drop and/or Cl drop? I'm assuming nothing happened to the CH?
 

Enjoying this content?

Support TFP with a donation.

Give Support
It's not the ending FC level, but the change in FC from adding hypochlorite that is relevant in terms of raising the pH. So it's really 32 ppm FC you added so closer to the +0.8 saturation index. That assumes the initial levels were correct.

If the cloudiness was caused by the raise in pH, then the pH dropping will have it clear up as will filtration. The FC itself is not relevant, but as the FC drops from chlorine usage/consumption, the pH will drop as well.
 
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply