BELOW IS A POST I COPIED AND THOUGHT I WOULD SHARE HERE. ORIGINALLY POSTED BY SHERRY13 ON A THREAD STARTED BY TIGGSY. FOR ANY WHO ARE CURIOUS.
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1188352&perpage=25&pagenumber=1
Hello,
I am very excited about this concept. I have the light pannel, the zip ties, the rock, the drill, the bits, the epoxy, the crushed coral and the Great Stuff. The problem is, to make sure Great Stuff would really work and be "fish safe," I wrote to The Dow Chemical Company, gave them a link to this thread and asked what they thought of the idea. Here is their response:
Dear Ms. Kennedy,
Thank you for contacting the Dow Chemical Company.
Our regular GREAT STUFF(TM) products would not be recommended for this type of an application. They will absorb water over time and begin to break apart with constant exposure to water.
Our GREAT STUFF Pond and Stone product would be a better product for this application. This product is resistant to water and would not absorb water with constant exposure to it.
Pond & Stone is a polyurethane foam adhesive that can be used easily and cost-efficiently to enhance your yard. The product can be shaped and molded to create exquisite water features that help direct water flow over and around rocks in a waterfall, rather than under and in between. The black color allows it to blend among rocks and shadows. The product is fish safe and recognized by the International Professional Pond Contractors Association.
Additional applications include use in filling holes in living trees and securing cap stones in stone retaining walls. The black polyurethane foam is designed to bond to both porous and non-porous rocks and stones in a cost efficient manner.
A quicker and less expensive option than mortar, GREAT STUFF Pond & Stone Waterfall Foam Filler can also be used to set and secure the cap stones in a retaining wall. The black polyurethane foam is designed to bond to rocks and stones.
This product is carried by the distributors below:
www.truevalue.com
www.doitbest.com
www.acehardware.com
www.orgill.com
Regards,
Katherine
Dow Customer Information Group
1-800-800-3626
8AM-4PM CST M-F
www.dowpolyurethanesystems.com
This information is considered accurate and reliable as of the date appearing above and is presented in good faith. Because use conditions and applicable laws may differ from one location to another and may change with time, recipient is responsible for determining whether the information in this document is appropriate for recipient's use. Since Dow has no control over how this information may ultimately be used, all liability is expressly disclaimed and Dow assumes no obligation or liability therefore. No warranty, express or implied is given nor is freedom from any patent owned by The Dow Chemical Company or others to be inferred.
So, I notice they do not say it's NOT fish safe. Mainly they are concerned about the integrity of the product over time. I will let my husband make the final decision (he's at work) whether to use pond foam or Great Stuff. I can hardly wait; this will be our best aquarium set-up ever!
But I've just got to say I love, love, love this whole idea!! All of the tanks on this thread are awesome! Keep up the great ideas everyone.
Sherry in WY