Blue dust/flakes in robovac

[svho]

Our pool is about 2 months old and I see the attached in the robovac consistently. Is it just the pool plaster getting settled in?

 

[PoolStored]

Our pool is about 2 months old and I see the attached in the robovac consistently. Is it just the pool plaster getting settled in?

View attachment 468726

Do you have a reliable test kit? If so, can you post results for your testing? (I know you are in NZ.)

 

[svho]

Do you have a reliable test kit? If so, can you post results for your testing? (I know you are in NZ.)

Hi, PH is about 7 (I just added some baking soda to increase that) and alkalinity is 80-100.

The stuff looks like flakes but breaks into sand when you rub.

Also, all other aspects of the pool are fantastic - eg, no sore eyes, rashes, algae, etc, etc. Very clean and clear.

Thanks!

 

[PoolStored]

Hi, PH is about 7 (I just added some baking soda to increase that) and alkalinity is 80-100.

The stuff looks like flakes but breaks into sand when you rub.

Also, all other aspects of the pool are fantastic - eg, no sore eyes, rashes, algae, etc, etc. Very clean and clear.

Thanks!

It is likely calcium carbonate flakes. I'm assuming that you have a Salt Water Chlorine generator. This will happen when pH is high, or when the pool temperature is high.

Do you have any way to measure CH in your pool? What is the water temperature of your pool water? Likely higher water temperature is driving you into scaling within the SWCG, creating the flakes.

You likely need to figure out your CH levels and reduce them. Without knowing your CH levels, will be hard to diagnose. The only way to lower is to replace water (see the "no drain exchange" Link --> Draining - Further Reading

If you can, and have a SWG pool, you should get this kit...they ship to NZ. Total Pool Water Testing Kit, Salt Water – Clear Choice Labs
If you have a chlorine (tablet or liquid chlorine pool), this is the kit. Total Pool Water Testing Kit, Fresh Water – Clear Choice Labs

You still need the kit, but borates can moderate the pH rise in side the SWCG cell that causes the scaling.

Borates in pool - Further Reading

www.troublefreepool.com

 

[svho]

It is likely calcium carbonate flakes. I'm assuming that you have a Salt Water Chlorine generator. This will happen when pH is high, or when the pool temperature is high.

Do you have any way to measure CH in your pool? What is the water temperature of your pool water? Likely higher water temperature is driving you into scaling within the SWCG, creating the flakes.

Thanks again. I have a "naked" / copper system. We have the pool at 29°C / 84.2°F

I looked up calcium flakes on my filter vendor website and they came back with this article - it all seems not possible though, because the pool is only 2 months old and PH has never been high?

 

[PoolStored]

Thanks again. I have a "naked" / copper system. We have the pool at 29°C / 84.2°F

I looked up calcium flakes on my filter vendor website and they came back with this article - it all seems not possible though, because the pool is only 2 months old and PH has never been high?

Yikes. You are working with a system we don't recommend for numerous reasons.

From the Vendor: "A NKD-R Pool System uses silver and copper to ionise your pool, keeping your swimming pool water free from algae, bacteria and other unwanted and harmful organisms."

Copper does not sanitize the pool, and can cause pool staining and green hair. The only way to remove copper is to replace the water.

Confusing is the link you sent, which seems chemically the same as our experience, but mentions salt water generator (salt cell). It is not really clear if you have a salt water chlorine generator or a copper ionizer.

 

[svho]

Thanks, but I already know you guys don't recommend that system.

Yeah I thought it was weird too, their article. I have a copper ionizer by the way.

 

[mgtfp]

Wondering whether that could be Copper Chloride (CuCl2)? As dihydrate that looks pale blue.

Any thoughts, @JoyfulNoise?

 

[JoyfulNoise]

Wondering whether that could be Copper Chloride (CuCl2)? As dihydrate that looks pale blue.

Any thoughts, @JoyfulNoise?

Doubtful. Copper chloride is highly soluble in water.

For a 2 month old pool I’d say come back at the end of the season and let us know if it is resolved. Could simply be plaster dust and calcium scaling. Put some white vinegar on it, if it fizzes like soda then it’s a carbonate mineral.

 

[mgtfp]

This seems to be the OP's system:

The Naked Pool System - Baring it all out

To start off, no, we’re not talking about skinny dipping. We’re talking about the Naked Pool System, a system which promises to change your pool experience forever.

www.mrpoolman.com.au

It points out that it produces also chlorine:

As water passes through the oxidizing plates, small untraceable amounts of chlorine is also released into the water ensuring that whatever isn’t killed off by the silver and copper ions (like body oils and other organic matter) are effectively eliminated from your pool water.

I particularly like how they point out the chlorine amounts are "untraceable", but still work as an oxidiser. Isn't marketing a marvellous thing?

The manual makes clear that some salt is required to run the system, and that the unit produces similar amounts of chlorine as a standard SWG cell (my one produces 35g/h, my old one produced 25g/h):

https://support.naked-pools.com/hc/en-au/article_attachments/1500008076361/Naked_Pools_NKD-R_-_Installation_Setup_Guide.pdf

That's where I'm thinking that releasing copper and producing chlorine within the same cell might enable copper chloride production?

 

[mgtfp]

But I agree with the solubility argument. So it most likely is just calcium carbonate created in the ionizer cell, maybe with some copper built in to give it the bluish colour.

 

[svho]

Wow, you guys know your chemicals. Thank you for explaining it all out!