Weird white stuff on my LR

[tjpontz]

I don't have a picture of this. My LR has been curing since Saturday. Yesterday evening there were white blotches on it in several spots, from the size of a coin up to about half the size of the palm of my hand. The white spots were almost like tightly woven spider silk or a thin milky substance, with holes through it down into the rock about like the width of the graphite in a #2 pencil.

Not every rock is affected.

Temp 77F
Ammonia 8
Nitrite 2
Nitrate 20
PH 8.2
SpecGrav 1.021

This is a 29 gallon FOWLR at this point. I have about a 5" DSB and the rock is Kaelini. No live critters in there (that I know of).

Any ideas guys?

[CrocoDillon]

Sounds like a sponge, but I'm no expert :D

[tjpontz]

Okay here's a little help with the visualization. Sorry if these aren't too clear, but it's all I have.

[tjpontz]

Sorry - let me try that upload again.

[tjpontz]

and a different angle of another spot.

Any ideas ?

[Duce]

It's probably die off.
My very fresh rock (the LFS just received them a few hours) gone through that as well

[tjpontz]

Thanks Duce. I "blew" the white stuff off my rocks with a turkey baster and very little has reappeared. My ammonia is down to 0.25ppm so I think I'm making good progress on my tank cycle. Trites and trates are still high though.

[R33f3r]

Dead sponges...

[coyoteseven]

I'll go along with R33f3r... looks like sponge die-off.