Rimless Tank Support

gtrider · Oct 23, 2018

All,

I have a 65g coast to coast custom rimless starphire glass aquarium that is currently in a cabinet with support around all the edges and across the whole bottom by a 1/8" piece of wood.

Question - do i need more support on the bottom? I'm nervous after reading the thread about the fellow who lost his 60g cube.

;Nailbiting

JumboShrimp · Oct 23, 2018

Do you have a photo or two to share?

Instigate · Oct 23, 2018

Post some pictures maybe? Without seeing it I would suggest adding some rigid foam board inbetween the pressboard and the tank.

gtrider · Oct 23, 2018

@JumboShrimp & @Instigate

Here's some pics. First one is from the side showing the perimeter support, and the 2nd two are from inside the cabinet showing the board and bulkheads.

JumboShrimp · Oct 23, 2018

... so what are the details about “the fellow that lost his 60g cube”? Did the bottom glass crack due to a ‘hollow’ or unlevel spot?

Instigate · Oct 23, 2018

gtrider said:
@JumboShrimp & @Instigate

Here's some pics. First one is from the side showing the perimeter support, and the 2nd two are from inside the cabinet showing the board and bulkheads.

What's the dimensions? A rimless needs tank needs flat support all across the bottom. Looks fine to me but I'm sure others with more experience will post. Do you have foam in between the tank and plywood?

JumboShrimp said:
... so what are the details about “the fellow that lost his 60g cube”? Did the bottom glass crack due to a ‘hollow’ or unlevel spot?

Looks like that guy didn't have plywood. The rimless tank was just supported on the edges I think.

Instigate · Oct 23, 2018

JumboShrimp said:
... so what are the details about “the fellow that lost his 60g cube”? Did the bottom glass crack due to a ‘hollow’ or unlevel spot?

https://www.reef2reef.com/threads/well-lost-my-60-gal-cube-tonight.483822/

JumboShrimp · Oct 23, 2018

There were a lot of possible causes discussed— ranging from overtightened bulkheads, to an unleveled tank, to a fallen rock. But if it gives you piece of mind, I happen to like this product. Of course, it’s cheaper if you don’t need a 72” length. Best wishes!

cromag27 · Oct 23, 2018

3/4” plywood on the bottom.

miPapareef · Oct 23, 2018

Can you place a straight edge or level on the plywood to see how much it is bowing (sagging in the middle)?

I think 1/8” plywood helps but is insufficient to support the tank and prevent bottom glass bowing.

I read that other post and I do think the bulkheads played a big role in addition to insufficient support causing the failure.

In one picture I see a long black (return pipe) going to your bulkhead. Is that pipe supported or is it be applying force on the bulkhead?

Instigate · Oct 23, 2018

gtrider said:
@JumboShrimp & @Instigate

Here's some pics. First one is from the side showing the perimeter support, and the 2nd two are from inside the cabinet showing the board and bulkheads.

Looking at the photos again I don't see any foam and the wood looks thinner than the 3/4" suggested by cromag.

JumboShrimp · Oct 23, 2018

I agree— 1/8” support on the bottom of a rimless tank that size would make me very nervous. 3/4” or even 1” while you’re at it. Personally, I’d go 3/4” marine grade, with the Innovative Marine mat to bring it all together for nice peace of mind

lapin · Oct 23, 2018

I would use 2 pieces. Bottom 1/2" ply then some thin rubber or foam then 1/2 melamine or some other type of coated MDF
If you win the lotto use a piece of granite counter top

gtrider · Oct 23, 2018

Instigate said:
What's the dimensions? A rimless needs tank needs flat support all across the bottom. Looks fine to me but I'm sure others with more experience will post. Do you have foam in between the tank and plywood?

Looks like that guy didn't have plywood. The rimless tank was just supported on the edges I think.

The dimensions are 36"x24"x18" and the glass is a 1/4" thick. There's no foam between the plywood and tank.

miPapareef said:
Can you place a straight edge or level on the plywood to see how much it is bowing (sagging in the middle)?

I think 1/8” plywood helps but is insufficient to support the tank and prevent bottom glass bowing.

I read that other post and I do think the bulkheads played a big role in addition to insufficient support causing the failure.

In one picture I see a long black (return pipe) going to your bulkhead. Is that pipe supported or is it be applying force on the bulkhead?

The long black return pipe is a black tube and it's flexible but i think i'll support it in the middle. it doesn't look or feel like it's adding any pressure on the bulkhead.

So is there a smart/recommended way to brace the tank now that it's already installed? It weights a ton, so it's not like i can lift it up and brace it.

gtrider · Oct 23, 2018

@miPapareef - there's no bowing. However the plywood isn't snug to the tank... i can press the plywood up in the middle to hit the tank... so it's really not supporting the middle.

I added a brace for the black return pump tube

Water Dog · Oct 23, 2018

Seriously, I’d break it down and replace the 1/8” plywood with 3/4” plywood with the leveling mat as suggested above. Clearly you paid a pretty penny for your custom tank. Support it properly. Save your custom tank and more importantly, prevent 65 gallons from ruining your house.

As an aside, are your sure that’s 1/4” glass? That seems awful thin for a tank of your dimensions IMO.

* Edit - If the 1/8” plywood is not flush to the tank, then your rimless tank is not being properly supported. You have a ticking time bomb on your hands unfortunately.

ca1ore · Oct 23, 2018

Before panicking, I'd suggest you ask the tank manufacturer. As I said in that other thread, a rimless tank bottom does not require complete support as long as the bottom was designed to not need support. In other words, it was thick enough. If the manufacturer says it requires full support, 1/8" plywood might as well be tissue paper for all the good it will do. You would need to use 3/4" with structural members at least across the middle and foam between thev tank and plywood.

I do think C2C will tell you full support is required, though I'd imagine the warranty is void on a DIY stand.

davocean · Oct 23, 2018

I have to wonder if that stand was really built for a trimmed tank, 1/8" ply is doing nothing for support of bottom as rimless typically needs.

I would drain the water into brutes, remove tank, make corrections.

It will be a headache to try to make corrections w/ tank on top of stand, and it would be a dangerous headache if tank was full.

3/4" ply is needed, and it should have a couple 1x or 2x braces under ply as well running front to back

gtrider · Oct 23, 2018

Water Dog said:
Seriously, I’d break it down and replace the 1/8” plywood with 3/4” plywood with the leveling mat as suggested above. Clearly you paid a pretty penny for your custom tank. Support it properly. Save your custom tank and more importantly, prevent 65 gallons from ruining your house.

As an aside, are your sure that’s 1/4” glass? That seems awful thin for a tank of your dimensions IMO.

Breaking it down is the last resort. I would prefer to brace it.

I was wrong... the glass is 1/2" thick. Nice catch.

gtrider · Oct 23, 2018

ca1ore said:
Before panicking, I'd suggest you ask the tank manufacturer. As I said in that other thread, a rimless tank bottom does not require complete support as long as the bottom was designed to not need support. In other words, it was thick enough. If the manufacturer says it requires full support, 1/8" plywood might as well be tissue paper for all the good it will do. You would need to use 3/4" with structural members at least across the middle.

I do think C2C will tell you full support is required, though I'd imagine the warranty is void on a DIY stand.

I called C2C at 5:15pm est this afternoon and they were gone for the day but i'll be making that call in the morning. I will go to bed praying they say that's it's fine.