Concrete to bond rock?

[Myka]

I imagine that's a poor idea since it takes so long to cure. I'm pretty sure it affects more than just the pH. I do believe it leaches something for awhile, but I'm not totally sure. I wouldn't try it.

[Veng68]

If you can get a hold of Thorite Cement (check with BASF (they are the big distributor) to find a local retailer).

This is a marine based cement and won't cause a pH change like normal cement. Google "Thorite Cement"..... there are many reef related threads about thorite.

Cheers,
Vic

[Veng68]

Sanjay Joshi used it on his big build....... check out his thread:

http://reefcentral.com/forums/showth...&pagenumber=26

Cheers,
Vic

[Delphinus]

Thorite! That's the stuff I was thinking of. I thought I read it was discontinued, but I can't find any info now to confirm that. Maybe it's more that I have no idea where you can get it. HD/Rona/etc doesn't seem to have it.

[Veng68]

This is BASF the main distributor of Thorite. Give them a try.
http://www.thoroproducts.com/

Charger Corp also distributes it
http://www.chargar.com/Products/prod_mf.html

Cheers,
Vic

[justinl]

IMO it would be perfectly fine to use relatively small amounts of portland cement. amount of cement relative to volume of water will determine how rapidly the cement will change the Ph, so it has to be considered on a case-by-case basis. You would just have to keep a closer eye on Ph for about a month than most people do on their tanks; I don't think it would be too hard to buffer or perform water changes to combat it.

[fishytime]

But then we have read about some of the DIY rock, where the recipe was off a bit and it wiped out peeps tanks....