Growth in Toilet Tank

[James Hudson]

Forgive me for this is my first post. I am wondering if any one knows what this "growth" in the toilet tank may be. It is a hard white substance that is at every penetration through the water line and around the rim of the water line on the edge of the tank. I've seen it occasionally and have disregarded it bu this tie it was much more pronounced. If it helps this was found in Central Texas about an hour north of Austin.

[Jerry Peck]

Mineral deposits from the water, calcium deposits as I recall.

[Garry Sorrells]

If the deposits are hard,
I would also say it is from minerals in the water that are building up at the surface line.
Something like a stalactite, stalagmite formation.

[Scott Patterson]

Did you ever make Rock Candy as a kid? Well this is not candy but it is a similar process...

[Lon Henderson]

Parts of Texas has heavily mineralized (hard) water. I grew up with that kind of water in Texas. Do you use this toilet often? A lightly used toilet seems more likely to get this sort of mineralized deposit. In any event, it's harmless, but a nuisance. Are you on a well?

If the "growth" is soft, spongy, etc., then it probably isn't mineral deposits.