CH level causing cloudiness when increasing pH?

vittoria

0
LifeTime Supporter
May 5, 2008
5
Northern NJ
I have an inground vinyl pool with a heater. I generally use the BBB method these days, but I occasionally use ph+ and calcium hypochlorite. (Poolife Active Cleaning Caplets which are just like the older Durations, mainly to finish off what we had bought in the past.)

Over the winter it has a mesh saftey cover so water and silt get in so it always needs lots of work when opened. We opened our pool in early May and due to "operator error" kept adding shock when it was actually so high it was bleaching the tests. (I had diluted the samples to see if that was happening but I guess I didn't dilute it enough at the time...oh well.) Once I got the chlorine under control I checked the calcium hardness and it was around 350, which was higher than the start of any other season I can remember. It usually starts around 200 and would inch up to 250-300 throughout the season when I was strictly using the calcium hypoclorite for sanitizing. I'm assuming all the calcium hypochlorite shock, and lots of it, may have caused the CH level to start off that high.

The chemistry of the water has been fine since early May, CH aside, and the water has been crystal clear. Because we've had so much rain this month I've had to adjust the pH upwards a bit a couple of times and since the TA was hovering at around 80 I felt it could benefit from the increase the pH+ would give it, as opposed to the Borax. The only glitch is that each time I immediately get the billowing white plumes in the water which eventually disperse but leave a slightly noticeable cloudiness which goes away after a day of filtering.

I'm assuming the instant cloudinesss after adding pH increaser is a result of the higher calcium hardness level. Is 350 high enough to cloud the water after adding pH+? I know I'd need to drain water to lower the level, but what CH level would be the higher limit that would not cause this to happen? (Not excited about major draining and rebalancing of all the levels again.)

Thank you.
Vickie


Inground vinyl 18x36 with Raypak heater

Per K-2006 test kit results:

FC 2.6
CC about 0
pH 7.4
TA 80
CH 330 (went down a little bit due to excessive rain.)
CYA 40
 
well, you know your fc is too low for your cya level right? probably not your current issue, but it can cause problems sooner than later. why did you think a TA of 80 was bad, or needed to be raised? that sounds great.
 
It could be. TA of 80 is fine if you are using bleach to chlorinate.

What were the PH readings when you added the PH +? If they were over 7.8 then certainly that could do it.

If PH is fine and one wants to increase TA you should use Baking Soda.

No more Cal-hypo, okay?

Keep your PH at 7.4-7.6 and you should be fine.

Cloudiness could be from the low FC level as Reebok mentioned. Do an overnight FC loss test to make sure your FC is holding.
 
Your description sounds exactly like calcium clouding, but your test results say that calcium clouding is fairly unlikely.

It might help to pre-dissolve the PH Up in a bucket of water and pour that slowly in front of a return jet with the pump running. That will mix the PH Up into the water much more quickly than the other approaches and can help to reduce the amount of calcium clouding.
 
I am not having a persistent clouding issue. The clouding happens the instant I broadcast pH+ powder to the pool. It makes these billowing white plumes which eventually disperse to create a very very slight clouding of my just previously crystal clear pool water. After a day or so it clears up. It has only happened on the two occasions I've added pH+ this year. I had this problem a few years ago when I was using only calcium hypoclorite. (Not sure what the CH was at that time.)

I added the pH+ because it measured 7.2 and I wanted it more around 7.4-7.5. My understanding was the TA should be 80-100, so my level of 80 was on the low end of that and I figured it wouldn't hurt to move it to 85 or so as well.

I think I'll drain/refill in small amounts here and there. Also, I'll try JasonLion's suggestion about premixing it and pouring it in front of the returns, if I feel it needs any more in the future.

I was hoping to get some sort of CH number at which this reaction would be expected. I know 350 is higher then it's been before.

As for the CYA/FC level, in general I normally have the CYA around 35 or so and I try and keep the FC around 3. I see from the chart that the desired level would be 5. I can honestly say I've never maintained a 5 and I've never had an algae problem...maybe I've been lucky.

My CYA is between 30-40. 40 would be max interpretation. It's probably really more like 35. I wish it weren't as subjective.

BTW, I had thought the old PoolForum was defunct and wasn't even trying to access it anymore, but I looked today and there it was with new posts. I was able to log in with my old ID there as well.

Thank you-
Vickie
 
That kind of clouding doesn't depend just on the CH level. It really depends on the calcium saturation index (CSI), which is a combination of PH, TA, CH, and a couple of other numbers. It is much more common to see cloding when your CSI is higher than yours is now. Your CSI is quite low, so I wouldn't normally expect clouding.

PoolForum.com was having some server access problems for a long while, but they finally got them cleared up a few months ago. It is still impossible for new users to register however.
 
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