Found Huge dry rock

[tcarter1936]

Score,I just bought a house and am in the process of a double tank build. I was clearing back some brush and found this tube shaped rock ,I'm concerned about what it may be. It looks like a sponge but weighs 50 lbs.
Amd strangely enough I found a pukani rock weighing 30 +lbs. I acid dipped but still see roots here and there . Any suggestions on how to proceed.???
Awsome peices just wanting to treat them properly first.

 

[Randy Holmes-Farley Verified Community Expert]

I'd put a drop of acid on the tube and see if it bubbles to see if it is calcium carbonate.

It might be a cement planter type of thing.

 

[Kevden31]

I'd put a drop of acid on the tube and see if it bubbles to see if it is calcium carbonate.

It might be a cement planter type of thing.

+1

 

[tcarter1936]

Definitely calcium carbonate.I dipped in acid and it went crazy. The very porous structure appears natural in every way. Started a fw soak.I'm more concerned with the roots and soil.this would make the perfect base for my 24 " tonga shelf