Calcium hardness inquiry.

[Macyc]

Hi everyone. My pool has been in great shape since finding this place and firing pool guy and taking it over myself a few years ago. I live in Florida and the weather started getting very sunny and warm over the past 6 weeks. For the start of the season, I cleaned salt cell, filter and checked all levels, including the ones I don’t check too often because water so clear/clean, isn’t much of a need to as I’ve gotten to know my pool.

My current numbers are:

Free chlorine: 6 (and very stable over months)
Ph: 7.9
Alkalinity: 90
Cya: I don’t currently know the number because I need to reorder chemical but as stated above, chlorine is stable.
Salt: 3400

I’ve noticed with my pool, the ph stays in the higher normal range (7.8-8.0 ish) when my alkalinity is above 60. I’m able to keep it at 7.4-7.6 easier when alkalinity is 50-60. But I learned from you guys, that’s understandable and leave it alone and let it lower in its own in time. Which it tends to do in warmer months and stay 90-110 in cooler months. I adjust ph when it’s 8 or higher.

Calcium hardness is 750. And it’s always been higher in this pool. I assume it’s the water where I live. I believe I recall someone telling me that isn’t anything to worry about or do anything about, am I making that up? That’s my question.

I have a Pentair easy touch and intellichlor salt generator. Pool and spa with spa flowing over into pool.

I do notice this white small substance blow into hot tub once a week and I just use pool blaster to vacuum out. I don’t know if it’s related to the calcium. I do not have scale on tiles etc. I do get calcium build up that’s noticeable on the salt cell when I clean it every 3 months. It’s pretty thick but, I am able to get it clean with vinegar/water. I have the white sediment in the spa now, I’ll attach a a pic and maybe someone can help me figure out what it is.

 

[PoolStored]

Get CYA reagents ordered.
I would replace water to get my CH down to 250.
Can you test your fill water for TA and CH please, and report.

 

[Macyc]

Do I test water the same way from hose I’d use to fill pool exactly as I would for pool? I’m going to assume that’s the case sorry if it’s a dumb question .

I am going to order new tonight. It’s on my list. In the meantime, with chlorine stable and pool clear, I have to assume it’s ok. Stabilizer isn’t something I tend to need often even if I still monitor it every other week or so.

 

[PoolStored]

Yep.
If you don't know your CYA you can't sanitize properly. CYA degrade 5-10 a month, faster if water is over 90.

 

[Macyc]

TA of water from outside hose that’s hooked up to house water is 60.

CH is 150.

Another odd thing is when doing the test from house water, it turned actual blue after 5-6 drops.

When using pool water it looked purple and not blue.

 

[Macyc]

Well the last time I checked it, it was 70. It’s been about two weeks. I typically keep my FC around 6-8 depending on use.

 

[PoolStored]

When using pool water it looked purple and not blue.

pH is different.

For TA and CH tests do you continue to add drops until the color doesn't change, then subtract that last dot?
If not test both again with this technique.

 

[Macyc]

pH is different.

For TA and CH tests do you continue to add drops until the color doesn't change, then subtract that last dot?
If not test both again with this technique.

Yes

 

[PoolStored]

If your fill water TA is 60 and your pool is 90...how did it get to 90.
With a CH of 150, it's not super high, but over time your CH will rise with evap and refill.

I'd get on the water replacement. You need to replace about 80% of the pool water.
Read "No Drain Water Exchange" here:

Draining - Further Reading

www.troublefreepool.com

 

[Macyc]

Thank you, I’ll read up on that. And post back with any questions. It sounds really hard.

I’ve no idea how it got to 90? Maybe I raised it months ago? I can’t recall last time I did so since it’s been between 80-90 all winter. And the only thing I add typically, or a majority of the time, is acid once a week or once every two. Maybe from how rainy of a winter we had? Maybe from the few years I used a pool service and who knows what they used?

For me, since coming here, it seems I keep my free chlorine level in check and cya. Ph adjustments at times. Brush, vacuum. Run robot. Kind of takes care of itself.

 

[PoolStored]

Post your Pool Water Temp and fill water temp. Post a full set of chemical results and I'll tell you where to drain and were to fill.
You have 25,000 gallon pool, 80% is 20K. Typical garden hose it 5GPM. 20K / 5GPM is 4000 minutes. 4000minues/60minutes per hour = 66 hours, or just less than three days.
You need a sump pump to pump out water. A simple sump pump from HD and a garden hose will work Do you have a place to send it (drain)?
You also want the sump pump to remove at closely the same rate as addition. If sump is too powerful, you can turn it on/off to keep the same level in the pool, or you can put garden hose over a ladder or other tall structure to reduce the flow from the sump pump to better match input with outuput.

 

[Macyc]

I’m going to get a pump today and start the process. Before I start I’ll test the water temps of hose and pool. Thank you very much. The white sediment settling on spa floor is driving me nuts

 

[Macyc]

there is a drain at the end of my driveway but it would be a long way from the pool. I do live on the river, is it harmful to drain it into the river? That may be a dumb question, not sure.

 

[PoolStored]

Drain it to the sanitary sewer if you can . The extra head will be helpful to balance input and output.

 

[Macyc]

Pool temp is 85.

Free chlorine is 6
Alkalinity is 90
Ph is 7.8
Cya is 50

How do I figure out the temp of water from hose?

Is that the pool levels needed or do I need to test anything else? My salt level is 3400

 

[Macyc]

Could my calcium hardness level be from hurricanes? A lot of river water dumped in during them. Or maybe it’s from a few years ago when pool was refinished. I still don’t get it but my salt cell gets build up on the monthly these days so I’m certain this is what’s blowing into the spa side and settling.

 

[PoolStored]

How do I figure out the temp of water from hose?

Meat thermometer, I have a nice digital that goes to .1 accuracy.

Could my calcium hardness level be from hurricanes? A lot of river water dumped in during them. Or maybe it’s from a few years ago when pool was refinished. I still don’t get it but my salt cell gets build up on the monthly these days so I’m certain this is what’s blowing into the spa side and settling.

Post a full set of results. FC, CC, pH, TA, CH, CYA.

 

[Macyc]

FC: 6
CC .5
Ph 7.8
TA 90
Cya 50
CH 750

Pool temp 85
Hose water temp 79

 

[PoolStored]

Are you using pool math?
Go to gear, upper right. Enable CSI, Enable Temperature, also share logs with TFP.
Test your fill water for CH and report.
Your CH is high. Could be from using cal-hypo, could be from years of using high CH input water and evap. I'd be surprised in FL with your rains.
I would replace about 60% of your pool water to get CH down to 250 (which is just fine for plaster pool).
After that, I'd work your TA down to 60-70. That will lower your CSI to be negative and your calcium scaling should go away.
Read "no drain water exchange" here:

Draining - Further Reading

www.troublefreepool.com