SquishyFish
Aquarium Advice Addict
I just wanted to update everyone on this stuff. I ended up using 4 cans on my falls (pics coming tomorrow hopefully.) Its very effective. It does exactly what the can says it will. Spray the "goo" between the rocks..it swells up immediately and drys with in minutes. 24 hours is almost rock hard. I would defintatly suggest it to anyone that is having problems with the water running behind the rock instead of down the front.