What is this sand/grit in filter basket?

[jbs11]

Hi all, I recently found some sediment/grit clumps in my filter basket. Does anyone know what this is?

Plaster? (previous owners had it re-done about 3 years(?) ago.

Tricolor puck residue? (maybe previous owners put them in skimmer)

Other ideas?

 

[Texas Splash]

Are you referring to those white chunks? Gather those up into a pile on the dirt or rocks somewhere and pour a little muriatic acid on it to see if it will fizzle. That would confirm calcium. Now if you are asking about the sand in the pic as well, we'll need to go further. What kind of equipment do you have? Your signature doesn't list anything. Do you have a sand filter?

 

[jbs11]

Thanks for the reply!
Yes, the white chunks. The sand is just the aggregate in the equipment pad
Yes, muriatic acid causes the chunks to fizzle/dissolve, great suggestion!
Where might the calcium be coming from? Should I be concerned? I have added some calcium chloride to bring up CH this year, but not immediately before i found this, and i did brush/mix thoroughly when adding. I have used Cal Hypo for my chlorine source for a while last year (to also help increase CH, before I had the SWG). Residual plaster from the resurfacing?

My CSI has been slightly negative this year, mostly driven by water temp (I open early b/c I enjoy the ~50* cold plunge), but not terribly so.

 

[Texas Splash]

Looks like you have some scale build up somewhere or it released. Possibly accumulated over the winter and is breaking loose now that you are open again.. Could also have been released by your SWG cell. You might want to inspect the cell for additional build up.

 

[jbs11]

Thanks again for the suggestions. I will check the cell and keep an eye out for more.