Decoration Weight Limit.

[ScalpCrabs]

I posted a thread about upgrading to a bigger tank a few days back.
I'm in the process of cycling it. 
My tank is a 30 gallon, W31 x D13 x H19.
Ive put some river rocks at the bottom and am planning on putting some rocks to make caves.
I'm worried about breaking the glass under it.
I've attached pictures to show the set up so far. 
Are there any precautions i should take (aside from cleaning the rocks and making sure there alright to put into an aquarium) before putting them in the tank. 


Are there any rules to follow aside from not putting an edge straight onto the glass. 

 

[Akasha72]

I've never come across a weight limit for decor in a tank. I've got large lumps of wood and big rocks in mind and had no problems. See what other think though

 

[ScalpCrabs]

Thanks for the reply
 
I didn't mention in the post that the river rocks are directly against the glass, don't know if thats bad either.
My last aquarium had gravel.
 
Also just so no one gets worried, the amp is broken and is strictly decorative, i would never subject fish to bass waves like that

 

[Akasha72]

I've used pretty much all the different types of substrate in all my tanks over the years - from rough gravel, to smooth pebbles and onto sand and none of it made a difference. All types of substrate are heavy - no matter what you choose. I doubt that the river rocks will be any different. Fish tanks are designed to hold immense weight and so common sense says it won't matter but please don't just take my word for it - please wait for other opinions. I'm not a structural engineer I'm just a girl using common sense and experience

I forgot to say ... all tanks are different. Some have solid bottoms and some have floating bottoms. That might make a difference to the weight limits 

 

[LyraGuppi]

You could try having a small bit of sand under the large decor to pad it.

 

[ScalpCrabs]

You think sand would help it spread the weight around?

 

[LyraGuppi]

In my opinion, but I may be wrong

 

[ScalpCrabs]

Alright thank you, I'll keep it in mind when I start putting the bigger rocks in.

 

[Akasha72]

yeah LyraGuppi has probably given some good advice there.It does make sense 

 

[NickAu]

What I did was use some plastic egg crate placing it in the tank first then put the rocks and gravel in. This is especially usefull if you have Cichlid's who love to dig.
 
This stuff.
http/www.totalplastics.com/assets/0000/2573/Eggcrate_large.jpg

 

[frapadoodle]

My only concern are the edges hanging off the edges of the amp. Most of the weight is distributed to the edges. Other than that, yes rocks are heavy, but mostly you should be okay.

 

[ShinySideUp]

I've always tried to keep rocks off the bottom and place them on a substrate instead. My thinking is that if the rock is against the glass then there is always the possibility of a point pressure as rocks are not even. Compare the imprint an elephant makes with it's foot in the ground and compare the potential damge with that of a woman wearing stiletto heel on a wooden floor; it takes a lot less weight to do the damage if it's concentrated into a point.

 

[ScalpCrabs]

Its only passing by 1 inch on each side on a piece of wood. do you think that is alright? Ill put the plastic stuff under the heaviest rocks

 

[Akasha72]

I would head to the diy store and get some strong wood that fits the entire tank bottom and then stand it on the amp if you want to. I would agree that the unsupported edges will be weak.

 

[frapadoodle]

It's much like load bearing walls in a building, but instead of supporting a roof, it supports the main weight of the glass, water, substrate, et cetera. It may not be today or next week, the weight will cause the ends to sag, and glass being glass it will break.
If you look at the wrought iron stands, it supports the edges of the tank. Don't get me wrong the idea of an amplifier as a tank stand is an original idea. And quite creative.