Why does a rimless tank need full bottom support?

[shoelaceike]

If the bottom glass on a rimmed tank can handle being supported on the perimeter, what makes rimless different?

 

[Ron Reefman]

Good question.

 

[piranhaman00]

The trim does all the work. On a rimless the glass does the work and thus must be evenly supported otherwise pressure points are created where some part of glass is doing more work and eventually....crack!

 

[shoelaceike]

The trim does all the work. On a rimless the glass does the work and thus must be evenly supported otherwise pressure points are created where some part of glass is doing more work and eventually....crack!

If you sit the bottom of the rimless on a perfectly level perimeter stand, wouldn't the stand act the same way a rim would? You could also use foam to compensate for any possible imperfections....I believe on a rimmed tank, the bottom is usually floating which means the silicone does all the work....this prevents the issue of the bottom sitting on any imperfections but the glass is still strong enough to support all the weight only being supported on the perimeter.

 

[Ron Reefman]

The trim does all the work. On a rimless the glass does the work and thus must be evenly supported otherwise pressure points are created where some part of glass is doing more work and eventually....crack!

What about a rimless tank that will sit on a stand with a hole that takes up all but about an inch around the rim?

 

[shoelaceike]

What about a rimless tank that will sit on a stand with a hole that takes up all but about an inch around the rim?

The rim on a regular rimmed tank is only there to make it easier to put together....i don't believe it has any structural benefit. I believe the weight of the tank is transfered to the side and the to the stand. That all said, the bottom holds the weight only being supported on the edges

 

[piranhaman00]

What about a rimless tank that will sit on a stand with a hole that takes up all but about an inch around the rim?

Cant do that. Full bottom needs support.

 

[Ron Reefman]

Cant do that. Full bottom needs support.

As the original poster asked... why?

Why does a rimmed tank not need support and a rimless tank does?

 

[shoelaceike]

Check out the Marineland rimless tanks. They use a fully open stand

 

[piranhaman00]

As the original poster asked... why?

Why does a rimmed tank not need support and a rimless tank does?

On a rimmed tank, all the pressure from the weight is exerted on the trim. Thus, only the trim needs to be supported.

On a rimless tank, all the weight is distributed evenly across the bottom pane of glass. Thus you need to support the whole bottom.

 

[Ron Reefman]

On a rimmed tank, all the pressure from the weight is exerted on the trim. Thus, only the trim needs to be supported.

On a rimless tank, all the weight is distributed evenly across the bottom pane of glass. Thus you need to support the whole bottom.

If the rimless tank is on a stand that has an open hole, then the rimless tank is only supported on the rim. Just like a rimmed tank. Your explanation makes no sense to me.

 

[piranhaman00]

If the rimless tank is on a stand that has an open hole, then the rimless tank is only supported on the rim. Just like a rimmed tank. Your explanation makes no sense to me.

Yes you are correct but there is no such thing as a rimless tank with open hole stand.


Please show example of open bottom true rimless? OP example probably has bottom trim but no top trim "rimless".

 

[BZOFIQ]

Is perhaps the glass on a rimless tank build around the base and with a rimmed tank it sits on top of the bottom.

IDK. Can someone who has removed the frame confirm?

 

[Gablami]

Rimless tanks can be supported by the edges. Case in point, elos rimless tanks with absolute stand.

this photo taken with panels off the cabinet.

photo from this thread:


Post in thread 'ELOS 120 Upgrade'
https://www.reef2reef.com/threads/elos-120-upgrade.543075/post-6645329

 

[Ron Reefman]

Yes you are correct but there is no such thing as a rimless tank with open hole stand.


Please show example of open bottom true rimless? OP example probably has bottom trim but no top trim "rimless".

You make too many assumptions.

I had a 120g rimless tank several years ago. but I sold it to downsize to a 40g tank.

Is perhaps the glass on a rimless tank build around the base and with a rimmed tank it sits on top of the bottom.

IDK. Can someone who has removed the frame confirm?

Rimless tanks come with either design. I think (not 100% sure) that all rimmed tanks have the side glass sitting on top of the bottom glass.

 

[Ron Reefman]

Rimless tanks can be supported by the edges. Case in point, elos rimless tanks with absolute stand.

this photo taken with panels off the cabinet.

photo from this thread:


Post in thread 'ELOS 120 Upgrade'
https://www.reef2reef.com/threads/elos-120-upgrade.543075/post-6645329

Thank you!

 

[BZOFIQ]

I think (not 100% sure) that all rimmed tanks have the side glass sitting on top of the bottom glass.

Rimless tanks can be supported by the edges. Case in point, elos rimless tanks with absolute stand.

this photo taken with panels off the cabinet.

photo from this thread:


Post in thread 'ELOS 120 Upgrade'
https://www.reef2reef.com/threads/elos-120-upgrade.543075/post-6645329

Beautiful setup. I believe the stand supports more than just "the rim". The top "lip" of the stand is wide enough to actually support the bottom pane as well.

 

[ca1ore]

As others have noted, depends on the tank design and material used. I’ve a deep blue glass frag tank that has no top trim but has a traditional bottom trim. Gets treated like a standard trimmed tank .... no full bottom support required. Conversely, my large acrylic display is eurobraced (thus not rimless) without any bottom trim, thus requirement from the manufacturer for full bottom support.

I’ve never bothered to check, but my guess is that traditional glass tanks that require support only along the bottom edges use thicker glass to compensate. Acrylic inherently bows more than glass and I’ve never seen one that is only supported by the bottom edges.

 

[BZOFIQ]

As others have noted, depends on the tank design and material used. I’ve a deep blue glass frag tank that has no top trim but has a traditional bottom trim. Gets treated like a standard trimmed tank .... no full bottom support required. Conversely, my large acrylic display is eurobraced (thus not rimless) without any bottom trim, thus requirement from the manufacturer for full bottom support.

I’ve never bothered to check, but my guess is that traditional glass tanks that require support only along the bottom edges use thicker glass to compensate. Acrylic inherently bows more than glass and I’ve never seen one that is only supported by the bottom edges.

Yeah, Acrylic tanks always required full bottom support because of bowing.

 

[Tenecor Aquariums]

Glass aquariums, both rimmed and rimless do not need full bottom supports PROVIDED the stand is 1) level, and 2) it is flat and 3) the seams are properly joined. Water pressure increases with the height of the aquarium and not so much with the width. Rimmed aquariums are usually constructed with thinner glass than comparable rimless and the rim provides structural integrity. Very large (large for glass that is) aquariums will sometimes have double thick bottoms. This is for two reasons - flexion and addional support.

Some companies provide a cushion with their setups. This is usually for making up for slight variations of the stand surface. The reason for their stands having solid tops is for practical design considerations. Flat full top stands are easier for retail customers to assemble.

We produce both acrylic and glass aquariums and recommend solid surface stands for all aquariums. Our aluminum profile stands provide plenty of support for glass aquariums but a solid top surface is better yet.