Greyish white gritty sand on bottom of pool

[jraymond1706]

I keep finding this sand like substance in our robot and when I bush bottom of pool it clouds up. I assume it is plaster our pool is about 23 years old and we’re plastering it next month. Store to think it could be that or it could also be sand? Can anyone tell me what they think it looks like and if it’s sand where could it be coming from? I don’t think it’s something blowing into the pool

30,000 gallon
Gunite pool with SWG

 

[ajw22]

Drip some muriatic acid on it.

If it bubbles it is calcium.

If it does not it is sand or dirt blowing into the pool.

 

[jraymond1706]

Drip some muriatic acid on it.

If it bubbles it is calcium.

If it does not it is sand or dirt blowing into the pool.

Thank you I’ll try that