The Puffer Forum

How much rock can you put in bottom of tank before breaking the glass is a concern?

Total guess here...

But I don't think you can "put too much" rock in a tank. Water is heavier than rock (more dense), so in my opinion, whatever water you displace with rock, will end up bringing the total weight of the setup down, albeit slightly. Someone please correct me if this doesn't make sense.

If you use egg crate or plastic with cross sections to spread weight/ avoid impact put as much as you like in. I never bothered tho and all is ok

There's a video on youtube of some guy stacking 200 pounds of slate rock in the bottom of an empty 10 gallon aquarium, then standing on it, and it still wouldn't break. That bottom glass panel is very strong.

I spent 1/2 hour this morning looking for that vid! Never found it...

Here it is !

Chuckfriedrice 1, Pufferpunk 0.

geronimo69 wrote:But I don't think you can "put too much" rock in a tank. Water is heavier than rock (more dense), so in my opinion, whatever water you displace with rock, will end up bringing the total weight of the setup down, albeit slightly. Someone please correct me if this doesn't make sense.

It's actually opposite Rock is much heavier than water.

Tanks are designed to hold a lot of weight for a long period of time. Given that marine tanks normally have a lot of rock I'm guessing those weights are safe long-term. I would put some sort of foam or egg crate over the entire bottom to protect the glass from the rocks, especially if a rock falls.

+1 to all the above which specify that rock is heavier (more dense) than water. It is.

But weight distribution is important. The biggest +1 goes to Flitter who specified that weight distribution does matter. It does, a lot. The danger from rock is mostly uneven weight distribution - small-point pressures can easily crack a tank, especially on the tank bottom, but also against the sides.

All high-rock-mass tanks should have eggcrate light diffuser panels on the bottom, or at least crushable foam boards.

The other factor significant to high rock mass in a tank is the net reduction in water volume. This also is non-trivial IMHO. All of my high rock nass tanks have secondary tanks (large sumps or whatever) to increase the circulating water volume to meet the fish's volume requirements. Pufferpunk's signature line that "the answer to pollution is dilution" refers to volume per fish as well as to water partial changes.

HTH

Thanks for the replies

RTR wrote:+1 to all the above which specify that rock is heavier (more dense) than water. It is.

But weight distribution is important. The biggest +1 goes to Flitter who specified that weight distribution does matter. It does, a lot. The danger from rock is mostly uneven weight distribution - small-point pressures can easily crack a tank, especially on the tank bottom, but also against the sides.

All high-rock-mass tanks should have eggcrate light diffuser panels on the bottom, or at least crushable foam boards.

The other factor significant to high rock mass in a tank is the net reduction in water volume. This also is non-trivial IMHO. All of my high rock nass tanks have secondary tanks (large sumps or whatever) to increase the circulating water volume to meet the fish's volume requirements. Pufferpunk's signature line that "the answer to pollution is dilution" refers to volume per fish as well as to water partial changes.

HTH

Thanks for the correction RTR! As I said earlier... total guess lol.

It would seem that aquarium manufacturers already know that we're going to see how much crap we can stack in the tanks, so they build them accordingly.

Wow nice.