White deposits on rocks

[Dave-T]

I have a 240 gallon reef tank, about 6 months old. Lately, I’ve noticed white deposits on the rock. It’s very white. My maintenance dude thought it could be calcium, but thought that would only happen if my calcium was high, and it’s only at 380. My alk is around 9. Anyone have any idea what this is? It’s in random spots on the rock, but mostly seems to have an affinity for the joints in the scape, which were done with e-Marco 400.

 

[thatmanMIKEson]

Is it soft?

Could it be a sponge?

 

[Dave-T]

No, it’s hard. Seems like some kind of mineral deposit.

 

[dwhanc00]

Did you ever figure out what this was? I have the same thing.

 

[Dave-T]

Yes, it was from super glue.

 

[dwhanc00]

That you put on the rocks or because you used superglue in the tank it caused the rocks in other areas to turn white?