Extremely high calcium hardness - Drain and refill? What to do while drained?

[exception4673]

My pool was built 4 years ago. It was filled then and hasn't been completely drained since. It's an in-ground, (from my estimate) 11000 gallons, pebble finish, with a SWG and a DE filter. Up until recently I was just using the home depot test kit and adding acid when necessary to decrease pH and adding salt when the SWG reported a low amount. Now I have a K-2006 test kit and a subscription to the pool math app, and I have been properly checking everything and trying to do things right.

My current levels are:
5.8ppm FC
pH of 7.8
80ppm TA
70ppm CYA
Calcium Hardness of 1100ppm

My calcium hardness is through the roof. After some reading of TFP and the K-2006 manual I did the various versions of the CH test to make sure I was getting an accurate reading. My sample is turning purple and then blue, but it never turns back to pink so I think that's correct.

So, now I'm thinking I need to drain and refill. That might be slightly overkill just for the hardness, but we also had very bad wildfires here in the Los Angeles area (as you may have seen on the news) and that left a LOT of ash in my pool. Now I worried about heavy metals and other toxic junk that may have come from the ash that I don't want to be swimming in.

My question is, what should I do while the pool is drained? Should I have it acid washed? I've heard lots of mixed things about this and I'm leaning toward not doing it. If not acid wash should I clean it some other way? Is there anything I should inspect while the pool is drained?

When I do refill I'm going to use part city water and part water from my home softener. I tested the water from the city using the same CH test and I got 320ppm, so with about 2000 gallons from my softener I'm thinking to dropping that down to about 260ppm which will give plenty of room for the level to rise with evaporation.

Thanks in advance.

TL;DR
4 year old pool, 11000 gallons, pebble finish, SWG
Hasn't been drained since it was built
Calcium hardness is very high, 1100ppm
Lots of ash from wild fires
Thinking about draining and refilling
Should I drain and refill?
If so, what should I do while the pool is empty?

 

[mknauss]

It would best to drain and refill.
Do NOT acid wash. Reduces life of your plaster finish dramatically.
Do you have scale on the plaster or water line?
How do you chlorinate?
Do you have a whole house water softener?

 

[exception4673]

There is scale on the tile at the water line. Not sure if there is scale on the pebble. Is that something that would be obvious? I chlorinate with the SWG. Yes my water softener is for the whole house but the hose bibs outside and the auto fill valve for the pool is not softened water.

 

[mknauss]

Is the plaster rough to the feel?
To get the scale off the water line you would use a blasting company. They can do it while the pool is drained if you timing it well.
You do NOT want to leave the pool empty very long.
You need to look how you can get softened water to your autofill.

 

[pjt]

It's an in-ground, (from my estimate) 11000 gallons

When you refill, note the start and end readings on your water meter. Subtract average household usage and you'll have an accurate pool volume.

adding salt when the SWG reported a low amount

I would recommend augmenting your K-2006 with a K-1766 salt test. Reported salt level from the SWCG can be unreliable.

Now I have a K-2006 test kit

Do you have a SpeedStir or other type of stirring device?

5.8ppm FC

Use the 10 ml sample so each drop is 0.5 FC. Saves time and reagents.

2000 gallons from my softener

Do you have a way of connecting your soft water supply to your pool fill line or another convenient means of getting soft water into your pool for top-ups?

 

[exception4673]

Is the plaster rough to the feel?
To get the scale off the water line you would use a blasting company. They can do it while the pool is drained if you timing it well.
You do NOT want to leave the pool empty very long.
You need to look how you can get softened water to your autofill.

No, it's not rough to the feel.
Is blasting the only method? I've heard of some chemicals or other methods for removing it.
Right, the heat can damage the plaster.
Getting softened water would be complicated, unless I just installed another softener for the pool.

When you refill, note the start and end readings on your water meter. Subtract average household usage and you'll have an accurate pool volume.


I would recommend augmenting your K-2006 with a K-1766 salt test. Reported salt level from the SWCG can be unreliable.


Do you have a SpeedStir or other type of stirring device?


Use the 10 ml sample so each drop is 0.5 FC. Saves time and reagents.


Do you have a way of connecting your soft water supply to your pool fill line or another convenient means of getting soft water into your pool for top-ups?

Yup that was my plan when refilling.
I'm using salt strips for now but once I run out of those I'll buy the Taylor salt kit.
I don't have a stirring device, but it seems like that would be a really nice thing to have.
Good tip I'll start doing that.
No unfortunately I would need to get another softener for the pool.

 

[pjt]

I'm using salt strips for now but once I run out of those I'll buy the Taylor salt kit.

Ditch the strips now and get the K-1766. Inaccurate information is counterproductive.

I don't have a stirring device, but it seems like that would be a really nice thing to have.

I would consider it almost mandatory.

No unfortunately I would need to get another softener for the pool.

Some people have had success with RV water softeners.