Calcium Hardness question

Total hardness and calcium hardness in pool water.
Scale, calcium buildup, hard water and scaling problems.
Shuggie
Pool Enthusiast
Pool Enthusiast
Posts: 16
Joined: Sat 07 May, 2022 03:22
My Pool: In ground pool, 10m x 5m, 72500 litres, pump: Astral Victoria Plus 38771. Sand filter. Mosaic tiles. Water is from private well.
Location: Menorca

Calcium Hardness question

Postby Shuggie » Tue 07 Jun, 2022 08:41

Over the last few weeks I’ve been working hard to reduce my CYA to an acceptable level and I’ve now managed to get it down to 62. I performed a SLAM at around 72 thanks to the advice on this forum and that has worked really well.

My next dilemma is the calcium hardness. I fill the pool from well water and always believed we had very hard water as we are always having to clean chrome taps in the house due to the white deposits and the kettle is always full of what I thought was calcium.

On testing the pool water I have a calcium reading of 11ppm, the source water from the well tests at 14ppm. I can’t test for TH as I don’t have the reagent.

I occasionally use my dolphin robot to clean the pool and in recent times have been left with a lot of scale looking like its come from the grout lines.

So I’m a bit confused. Do I trust the calcium test I have done with my ‘pool lab 1.0’ ?

I didn’t want to rush out and buy a load of calcium increaser until I get some advise on here.

Here are my numbers,

Alk - 111
PH - 7.4
Fc - 12
Cc - 0.28
CYA - 62
CH - 11

Now just using liquid bleach.

Should I be raising the calcium level?


Teapot1
Pool Industry Leader
Pool Industry Leader
Posts: 1175
Joined: Thu 29 Apr, 2021 00:43
My Pool: 12000 gallons vinyl liner,

Re: Calcium Hardness question

Postby Teapot1 » Wed 08 Jun, 2022 01:37

Hmm, your pool lab is a good bit of kit but I understand why you wouldn't want to pay out for the upgrade and reagent. I would suggest a cheap water hardness kit from an aquarium shop or on-line retailer. It could well be dissolving grout but that wouldn't explain your taps so a second different test for TH. I have only come across water that soft in an area of the Dordogne where a drop of washing up liquid would last and last and it was difficult to rinse soap off.
I may not give you the answer you want to hear, but I will give an honest opinion of your situation as you decribe it.
Shuggie
Pool Enthusiast
Pool Enthusiast
Posts: 16
Joined: Sat 07 May, 2022 03:22
My Pool: In ground pool, 10m x 5m, 72500 litres, pump: Astral Victoria Plus 38771. Sand filter. Mosaic tiles. Water is from private well.
Location: Menorca

Re: Calcium Hardness question

Postby Shuggie » Wed 08 Jun, 2022 04:25

So I went to my local pool store (the biggest and main one in the area) and asked the for a TH test. The young man looked at me as though I was speaking Chinese. He had to ask the boss and the answer was no. A few weeks back when I asked for liquid bleach they said ‘we don’t sell much of that it’s mainly used by the service guys to clean terraces’. I asked if they sell Borax or boric acid, not sure what language I was speaking then, but they had no idea what I was talking about. They must think I’m a bit strange :lol: :lol: I’ll try my local aquarium store and see if I have better luck.
Shuggie
Pool Enthusiast
Pool Enthusiast
Posts: 16
Joined: Sat 07 May, 2022 03:22
My Pool: In ground pool, 10m x 5m, 72500 litres, pump: Astral Victoria Plus 38771. Sand filter. Mosaic tiles. Water is from private well.
Location: Menorca

Re: Calcium Hardness question

Postby Shuggie » Wed 08 Jun, 2022 05:46

This is the stuff that’s coming out of the robot cleaner basket.

D560CDBD-D419-4E25-9439-52C5E7F7A623.jpeg



EE58BAFC-F615-4570-BDD4-8FE8B4873D41.jpeg
Teapot1
Pool Industry Leader
Pool Industry Leader
Posts: 1175
Joined: Thu 29 Apr, 2021 00:43
My Pool: 12000 gallons vinyl liner,

Re: Calcium Hardness question

Postby Teapot1 » Wed 08 Jun, 2022 10:44

On the contrary, you are sound its the pool shop that are strange! (Read uneducated idiots and con artists)
I may not give you the answer you want to hear, but I will give an honest opinion of your situation as you decribe it.
Teapot1
Pool Industry Leader
Pool Industry Leader
Posts: 1175
Joined: Thu 29 Apr, 2021 00:43
My Pool: 12000 gallons vinyl liner,

Re: Calcium Hardness question

Postby Teapot1 » Wed 08 Jun, 2022 10:46

Hmm needle like calcium structure? Try dissolving them in vinegar/ lemmon juice, or descaler?
I may not give you the answer you want to hear, but I will give an honest opinion of your situation as you decribe it.
Shuggie
Pool Enthusiast
Pool Enthusiast
Posts: 16
Joined: Sat 07 May, 2022 03:22
My Pool: In ground pool, 10m x 5m, 72500 litres, pump: Astral Victoria Plus 38771. Sand filter. Mosaic tiles. Water is from private well.
Location: Menorca

Re: Calcium Hardness question

Postby Shuggie » Wed 08 Jun, 2022 13:36

So if I do that will it prove that it’s high in calcium?
Teapot1
Pool Industry Leader
Pool Industry Leader
Posts: 1175
Joined: Thu 29 Apr, 2021 00:43
My Pool: 12000 gallons vinyl liner,

Re: Calcium Hardness question

Postby Teapot1 » Wed 08 Jun, 2022 15:32

No that was just to see if it does dissolve. It could be magnesium or calcium but from the colour I am favouring magnesium so a total hardness less your calcium hardness maybe a clue.
I may not give you the answer you want to hear, but I will give an honest opinion of your situation as you decribe it.
Shuggie
Pool Enthusiast
Pool Enthusiast
Posts: 16
Joined: Sat 07 May, 2022 03:22
My Pool: In ground pool, 10m x 5m, 72500 litres, pump: Astral Victoria Plus 38771. Sand filter. Mosaic tiles. Water is from private well.
Location: Menorca

Re: Calcium Hardness question

Postby Shuggie » Fri 10 Jun, 2022 02:48

I’ve ordered the reagent for TH test and will do as you suggest. After a little bit of research I read that high magnesium in water can lead to greenish/blue scale residue. That fits with the stuff I’m getting in the robot basket. I’ve also got the same colour scale in my dogs metal water bowl so it all seems to be pointing to high magnesium in the well water. I’ll report back with TH results when I get the reagents.
Teapot1
Pool Industry Leader
Pool Industry Leader
Posts: 1175
Joined: Thu 29 Apr, 2021 00:43
My Pool: 12000 gallons vinyl liner,

Re: Calcium Hardness question

Postby Teapot1 » Fri 10 Jun, 2022 05:56

:thumbup: :thumbup:
I may not give you the answer you want to hear, but I will give an honest opinion of your situation as you decribe it.

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