Something doesn't make sense here...need advice

[bigwillokc]

I am constantly battling my water chemicals and I understand that rising pH is just something you have to deal with, but I am having some strange issues that I am not sure how to deal with.

First of all my pool is very clear, not cloudy at all and no sign of algae or anything with regard to that. CC is always testing 0 on all my water tests.

Gunite pool right around 35,000 gallons

For reference, here are all of my test results from this morning:
FC - 4.6
CC - 0.0
pH - 7.8
TA - 100
CH - 470
CYA - 60
Salt - 3000
Borates - 15
Temp - 84
CSI - 0.28

Problem #1. It seems like I have a very high CH level in my pool. I tested the water out of the hose this morning and it was showing CH of 80. Seems that my CH is way higher than the fill water for some reason.

Problem #2 and this is the one that really has me worried. My pool has TONS of what i have determined from googling this form to be Calcium scales. I have zero sign of scaling on my waterline, walls, tiles, etc, but there are a ton of these scales in the form of piles of white flakes just resting on the bottom of the pool, in the corners, hot tub, etc. I cleaned out all the filters and even the SWG yesterday and it didn't really have anything on the SWG plates either. My pH did get out of hand for the past month or two and I ended up having to add over 2 gallons last week to bring it down. Could that have prompted the scaling to come loose from where ever it was?

According to my CSI, I'm in good shape, but how do i clear up the calcium scales? Do i just need to clean them out and keep an eye on it? This is the third summer since getting the pool installed and I have never drained any of the water and refilled. The pool math app is calling for me to drain and replace 50% of my water. I'm wondering if this might be a good idea to see if the levels come down and become more manageable?

A couple of pics attached for reference!

 

[jtpipkin]

i'll let others address the calcium, but is there a reason you're borates are only at 15?

 

[Jimrahbe]

Will,

I suspect that you keep knocking your pH down to 7.2 .. Most SWCG pools like their pH at 7.8, so you should just try to keep it there.. Better to add a little MA more often than a bunch of MA all at once..

Thanks,

Jim R.

 

[Divin Dave]

Hi bigwill,
check out this thread... it seems you might have the same thing they did.

Pool opening and robot filled with crytsal substance

So for the second opening of our 2.5 year old pool, the dolphin cleaner pulled a ton of this bluish crystal substance. When it dries it became white. See attached pictures. Is this normal or an indicator that I need to do something to the water chemistry over winter or when closing/opening...

www.troublefreepool.com

 

[bigwillokc]

i'll let others address the calcium, but is there a reason you're borates are only at 15?

I'm not really sure why they are that low. I added a ton of boxes of borax last year but i'm not really worried about the borates now as i have read i should get all of my other chemistry in order before correcting borates since it may make ph management more difficult. also if i need to replace water i don't want to waste it. It was at 30 last year though

 

[duraleigh]

Are you now or have you used Calcium Hypochlorite (it's granular) to chlorinate or "shock" your pool

 

[bigwillokc]

Are you now or have you used Calcium Hypochlorite (it's granular) to chlorinate or "shock" your pool

Never that i can recall. We had a bad algae issue last year (i have since learned that the SWG doesn't work when water temp is too low lol). But when i shocked then and cleared up the algae it was all with jugs of liquid bleach.

 

[bigwillokc]

Will,

I suspect that you keep knocking your pH down to 7.2 .. Most SWCG pools like their pH at 7.8, so you should just try to keep it there.. Better to add a little MA more often than a bunch of MA all at once..

Thanks,

Jim R.

Should I not be trying to drop it to 7.2 and aerate to lower my TA?

 

[Jimrahbe]

Will,

There is a process to lower your TA and then there is the routine of maintaining your pH.. In my mind, these are two different things..

If you add MA it will reduce both your pH and your TA.. Aeration will then bring your pH up and leave your TA as is..

If you are constantly running aeration, then that is just one reason your pH is being driven high..

There is no reason to lower your TA to just meet a number.. If you can maintain your pH at 7.8, then I would leave your TA alone..

If you really just want to lower your TA, follow this process... It takes a couple of days of work to get the TA to come down quickly...

Measure and record your pH and TA... Turn on your aeration and leave it on... Add acid to reduce your pH to 7.1 or 7.2.. Measure and record again in about 3 hours.. If your pH is above 7.4, add acid to reduce it to 7.1 or 7.2. Keep doing this every 3 hours or so.. You will find that the TA will come down just a little at first, but as the day goes on the TA drop will get larger and larger. Keep this up until your TA gets to 50 or 60... It will spring back up 10 ppm pretty quickly on its own.. But, as long as the TA is above 50 you are good to go..

Thanks,

Jim R.

 

[bigwillokc]

Thank you! And as far as all of the existing calcium in the pool/water, i'm assuming just let the pool cleaner keep cleaning it and it will eventually stop showing up as long as the CSI stays in the acceptable range?

 

[duraleigh]

• Thank you! And as far as all of the existing calcium in the pool/water, i'm assuming just let the pool cleaner keep cleaning it and it will eventually stop showing up as long as the CSI stays in the acceptable range?

  Not True!!

Reinforces one of my pet peeves about folks relying on csi as a crutch for pool care.

Once Calcium is in your pool, it does not come out unless you drain off water and refill with water that has less calcium. CSI has nothing to do with calcium accumulation or reduction and will not help you.

So, here's the skinny....

1. If the CH of your fill water is truly 80, you have no issues in the future.

2. A CH of 470 is not all that high to begin with and can be carefully managed with pH and TA.

3. However, Your CH should never have been that high to begin with. With a little over 3 feet of annual rainfall (CH virtually zero), and a refill CH of 80 ppm, I would expect your CH to be below 200. Where did that CH of 470 come from if you didn't put it in there......I don't know.

My suggestion is that you continue to search for the source of your CH (test bi-weekly and record your refill water and rainfall) and keep your pH down around 7.4 or a bit lower. Once you have stabilized your CH readings, then you should work towards physically removing that calcium scale.

 

[Jimrahbe]

Dave,

It may just be a matter of semantics, or my lack of chemical experience, but...

When I let my CSI get away from me, I get the calcium scale flakes in my pool, just like the OP.. My robot sucks them up and they do not seem to have any effect on the CH level..

Getting my CSI back to normal will eliminate the flakes from happening..

My CH level is the same, with or without the flakes... They bubble when I add them to MA, so I am assuming they are calcium..

That is just a fact of life for me...

Thanks,

Jim R.