Brushing detaching inter-tile grout

[Torrente]

Hello, 3 months ago coinciding with a big overhaul in equipment room I regrouted the tiles gap with Laticrete 1600.
I brush the pool weekly and every week I notice a relevant amount of grout being detached that is visible blurring the water with the grout color. Initially I thought that was normal considering the recent work but after 3 months continues the same and some tiles separators are starting to be visible.
I have SWG and at the time of filling the pool I didn’t know about curing process and I added salt since the very beginning. Maybe this is the problem...

I would appreciate any idea/suggestion.

My current water analysis is:
FC 5
CC .5
pH 7.5
TA 60
CH 425 (I have soft water and lot of rain and I have to add a lot of Ca Chlor Dihid frequently)
CYA 70
Salt 4000
BOR 50

 

[ajw22]

It is not clear to me that the Laticrete 1600 grout you used is suitable for underwater pool tiles. I have used Pool Tile Grout Repair Regular Set - White for pool grout repairs.

 

[zea3]

You have to allow Laticrete 1600 to cure 14 days before submerging in water, as per this data sheet: https://laticrete.com/~/media/support-and-downloads/frequently-asked-questions-files/lds2580.ashx?la=en

You need to use a grout specifically for swimming pools.

 

[Torrente]

That is the grout prescribed and used by my pool builder, it seems that I have a problem here...
Considering the current situation that it has been already underwater for 3 months, any advice about what to do to mitigate it?
Should I stop brushing provided that I have a clean surface?
Would it end curing underwater?

 

[ajw22]

If it has not cured in 3 months it is not likely to improve.

Stopping brushing will not be good for the tile and can allow algae to take root.

Eventually you will need to drain down and redo the grout using proper materials.

 

[Flying Tivo]

Platinum 254 and Spektralock pro are the recommended adhesive and epoxy grout. If you use this combination they will warranty 25 years. It's what I used.

 

[Torrente]

Would it make sense to drain the pool and let it cure?

I can not do it now as we are in rainy season and we have heavy rain most of the days, but it might be a possibility in January or February. As we use the pool every day I would do it only if dry season would coincide with a family travel, it would have a cost as while water is almost free here (I would not feel good dumping that amount of water on dry season) the chemical additions would amount around 500$ (salt, ca chloride dihid, boric acid)