Live rock on eggcrate, sand or on bottom?

[Aquattro]

Originally Posted by jtbadco

It's not rock falling and breaking the glass that you need to worry about. It is having all the weight of the rock above focused on the tank bottom thru one grain of sand.

If even one grain of sand gets between the LR and the glass bottom it can focus all the weight above onto that one spot.

Not worth the risk IMO.

Here's a quick calculator...

$10 for eggcrate or oyster shells (in my case) divided by cost of broken tank, loss of all inhabitants...fish, corals, LR, damage to house, floors and hassle of clean up.

Easy math

I'm sorry, but that fringes on ridiculous. The rock is not going to focus it's mass on one grain of sand and break glass. ""IF"" it focused that much mass on a single grain of sand, the sand will crush. Or it will puncture into the bottom of the rock. Or get squeezed out sideways.

I have always laid my rock on bare glass. I've dropped 5 pound pieces of rock in the tank (with water) and had it hit glass. The eggcrate is not dispersing weight to save glass. Just not happening. My holding tank has 3/8" glass on the bottom, I filled it for months with 140 pounds of rock that I flipped and flopped around while rummaging for certain pieces.

Here's an example. I needed to remove a cross brace from a tank. Figured a hammer was the quickest way. It was utterly amazing the force I had to hit it with to actually break it. A rock tumbling 8 inches in water to rest on your glass is not going to break anything but corals.

I have seen once, and only once, where a rock, about 40 pounds, fell 2' in huge tank and actually broke the bottom.