pre-vacation numbers & calcium related cloudiness?

[HoustonMom]

Hi there! Thanks in advance for looking over my numbers. Going on vacation and have just started paying attention to CSI because I think I have a calcium deposit on my grout.

FC= 6
CC =.5
TC =6.5
PH=7.5
TA=80 (until recently 100 -- I lowered it today with M. Acid in reaction to CH and CSI worries)
CH = about 450
CYA = about 45
CSI = .09 (was around .5 this morning - could that be right?)

This morning while brushing the pool I noticed a small white patch about the size and shape of a caterpillar on a grout line. I chipped it off. Is this calcium? I'm guessing it is calcium because of the high CH reading. :idea:

Another reason I believe it's calcium: My son told me two days ago he noticed decreased clarity when opening his eyes underwater, a whitish haziness. I don't think it's algae since cc is .5.

The CH and CSI were both elevated as of this morning. After lowering TA to 80 with one addition of muriatic acid, the CH is the same and CSI went to .09 (does this sound right? I have never paid attention to CSI until today, not sure what makes sense yet. I don't want to mess up my pool/equipment with calcium scaling!

I read that I can either (1) partially drain to address the high concentration of calcium, or (2) lower TA. I tried the route of lowering TA and got it to 80. Is that enough to fix the calcium problem? In general, what should my strategy be to get the right CSI, CH, etc. going forward? I feel like PH is always trying to rise in my pool. The PH of our fill/tap water is 7.8 which explains why it would be 7.8. Often when I check it is around 8 or higher.

Finally, we leave Wednesday for a ten-day vacation, during which the pool will be dosed with 64 oz. liquid chlorine every other day (8.25%). (I use about 220 oz chlorine weekly in summer). Every four days (every other visit) 30 ounces of muriatic acid will be added. Any observations about this plan would be appreciated.

Thanks everyone!
HoustonMom





I reduced TA

 

[linen]

CSI = .09 (was around .5 this morning - could that be right?)

Yes, if your ph was 7.8. A csi of 0.5 (if it does not go higher) is not horrible but having it down at 0 is better.

This morning while brushing the pool I noticed a small white patch about the size and shape of a caterpillar on a grout line. I chipped it off. Is this calcium? I'm guessing it is calcium because of the high CH reading.

Posting a picture might help. It could also be efflorescence.

Another reason I believe it's calcium: My son told me two days ago he noticed decreased clarity when opening his eyes underwater, a whitish haziness. I don't think it's algae since cc is .5.

Just because CC is less than 0.5 does not mean that you don't have algae. I would bring the pool up to your SLAM level tonight (16 ppm FC per poolcalculator) and do a OCLT to determine if it is algae or not. I would not bet on calcium clouding with your values?

Your calcium level is really not too high as long as you monitor and keep your ph lower, you should be fine.

Do you know what your fill water CH level is?

What is your primary source of chlorine?

 

[HoustonMom]

Thank you for answering so quickly. I have used liquid chlorine (bleach) for about a year now, with great results. Pool has been in service a year and five months - those first five months felt like a lot of guessing and overdosing. Happy to be following this program of pool management.

Our fill water has calcium hardness of 140. Glad to hear the pool's calcium hardness is not that far out of whack. I will try bringing pool up to slam level tonight and seeing what comes of that.

This is a photo of the unidentified white substance on my grout.

[attachment=0:ihg2wf27]pool.jpg[/attachment:ihg2wf27]


P.S. I'm thinking of diverting rainwater from the roof to the pool for all the low- or no- calcium water I can get. That would also help with salt buildup over time (and cya though I don't use pucks). I truly want a trouble-free pool.

 

[linen]

That sure looks like efflorescence to me and has nothing to do with the CH. You should be able to remove it with a diluted 1:3 solution of Muriatic Acid (1 part 31.45% MA, 3 parts water), though often efflorescence continues to happen again over time.

Salt buildup isn't a problem and if you don't add more than you should, cya isn't a problem either. Your fill water CH is fine...were you using cal-hypo at one point to chlorinate?

I would do the OCLT, so that you know if you have an algae issue or not. Sorry about the link for the OCLT above here it is linked correctly: http://www.troublefreepool.com/pool-school/overnight_fc_test

 

[HoustonMom]

Linen, thank you so much for your help. Especially since we leave for vacation soon and I really needed answers!

A good old-fashioned algae outbreak I can handle -- but less so calcium scaling.

Yes, I did use pucks for maybe four months when the pool was first opened.

Last question: Can I keep the TA below 100 (it's currently 80) in the interest of avoiding scaling? I realize the recommended range is 100-120. From my reading on TFP I've gathered that keeping TA low will stop PH from climbing so steadily. Is around 80 good or what is ideal PH/TA balance?

Many thanks again, your help has been invaluable!

 

[duraleigh]

That sure looks like efflorescence to me and has nothing to do with the CH.

I agree....it is unrelated to pool water chemistry and is coming from behind your tile.

 

[JohnN]

The recommended level for TA in a bleach chlorinated pool is 70-90 ppm.

 

[linen]

Yes, in fact you can continue to move TA down even more if it will help ph to stabilize. I would not go below 60 ppm though. There is no ideal since each pool is different. Since your pH is already fairly low, I would just watch it and drop it to 7.2 whenever it gets to 7.6. This will slowly decrease TA and at some point you may find that the ph is not rising anymore...and you have found your sweet spot.

So you have used no calhypo...then maybe all of the CH is from when the pool was built and first stabilized?