Breeze block stand advice

[Andrew Yeoman]

hi all, first time posting on here.

Just building a stand for a 8x3x2 tank, and wondered if I'd be able to build with breeze blocks, floor joists (3x9") plywood and foam, without cement on the blocks? Or will I need it?

I've seen cars held by such blocks and imagined the 1.5 of weight would be sufficient weight on the block stand. The block btw are 8" high, with hollow parts. (Not the smaller 4")

Please advise, thanks
Andrew

 

[BIG-G]

First off welcome to MFK.
I had to look up breeze block. Lol never heard that before. Cinder block here.
I have seen a few stands built with these block just stacked and boards laid across the span. No cement used.
A LFS near me has the whole store setup like this. This is all with smaller tanks though.
I don't have any doubt they can hold the weight my only concern would be if someone were to bang into the stand or push on it that it may topple.
As long as there are no way to push it over I would give it a try.

 

[Dieselhybrid]

What kind of tank? Glass or acrylic. Neither needs foam. Do you plan on putting the foam under the tank? If it's glass, please do not do this. If it is acrylic, there's a debate, but it's not needed. Neoprene is acceptable if one insists.

You don't want any other type of foam under acrylic. The problem is if you chose to put heavy rocks or anything inside the tank with weight, it usually isn't evenly distributed on the bottom panel. The weight is mostly to the middle. If the bottom acrylic pane is on a "soft" surface it will bow downward into the foam in the center. This makes it no longer flat, as the corners are higher (vertically) than the middle of the pane. This matters because that bow makes the seams no longer a true 90 degrees while resting. This means stress. They widen over time and stress the joint, it's literally pulling the bottom seams apart slowly. With older tanks this causes issues, especially if they are capillary welded

 

[BIG-G]

I have to disagree. Most acrylic tanks are set up with a panel underneath and some people use foam and some do not. As long as the tank is fully supported and level from front to back and side to side.
With glass tanks it's the same they have to be level and fully supported.
If the glass tank has a frame you do not have to use foam.
But if it doesn't a layer of foam is advised to stop there being any pressure points on the bottom and to allow the foam to crush down insuring perfect level.
I have made most of my tanks myself they do not use a bottom frame the glass sits on a sheet of foam. But again you have to insure the tank is leveled properly.

 

[Dieselhybrid]

Those dimensions are roughly 360 gallon tank which is roughly 2870lbs of water plus the weight of the tank itself. The cinder blocks will hold and can build an adequate stand, but they aren't always true and have some variation. One stack of 5 blocks can be roughly taller than another stack, I've gone through this building stands to build acrylic tanks on. I would just build a wood stand for around 100-200 bucks. You can easily do it in 1 day. That way you can have storage underneath, which should be used for a sump on a tank that size, and you build to specs with precision. This way you can make a stand that is true will properly support your tank without risk of stress over time from imperfections.

My opinion is do it right and do it once. Start where you will finish.

 

[Dieselhybrid]

You can disagree you are free to do so. It is important to be sure when giving advice regarding pressurized vessels, there's a lot at stake here. Everything I know about tank building and setup comes from James Steele "Acrylics" over at reefcentral. He founded Envision Acrylics and has been building tanks for 30 years. He was the one to first share the pin/shim method in a thread on that forum, it's been running for over 10 years and is so big it's been split into multiple threads and archived. He speaks at length over this topic and I choose to follow his logic as I don't tolerate excess risks. I will admit I am very conservative with risks, likely because of the stock I'm responsible for.

You can do whatever you choose, you can give advice to people all you want. It's up to them to decide what is a credible source. I'm not going to copy and paste from there, or explain much further. But there are many acrylic aquarium manufacturers that will immediately void your warranty for placing a tank on the foam you have pictured. I know that tank is glass but someone may not clearly understand looking at this thread. Everyone is free to believe whatever they choose.

The "proper" bottom for an acrylic tank is double 3/4" plywood with screws impact driven and recessed so the screw heads do not make pressure points on the bottom of the tank. If the screws or abnormalities cannot be fixed, then use neoprene as it truly makes an even surface. The foam pictured is wrong regardless if many people do it. Many people in agreeance is a function of power, not truth. Everyone once believed the world is flat, didn't make it any more true. The foam pictured doesn't have enough structural density for larger 300+ gallon acrylic tanks, it breaks down over time and compresses. especially around the edges. Sure the tanks will hold for 5, 10, years. But they'll craze way sooner than properly mounted tanks, the seams will start to craze out and get white separation spots, eventually leading to prematures failure. I just don't get it? Why do something just ok or adequate? Why not do everything the best possible way? Especially if it isn't that much more expensive or time consuming? I'm old school

Yes, rimmed glass tanks don't need foam, for rimless foam can be used but again neoprene is a better material

 

[BIG-G]

You can disagree you are free to do so. It is important to be sure when giving advice regarding pressurized vessels, there's a lot at stake here. Everything I know about tank building and setup comes from James Steele "Acrylics" over at reefcentral. He founded Envision Acrylics and has been building tanks for 30 years. He was the one to first share the pin/shim method in a thread on that forum, it's been running for over 10 years and is so big it's been split into multiple threads and archived. He speaks at length over this topic and I choose to follow his logic as I don't tolerate excess risks. I will admit I am very conservative with risks, likely because of the stock I'm responsible for.

You can do whatever you choose, you can give advice to people all you want. It's up to them to decide what is a credible source. I'm not going to copy and paste from there, or explain much further. But there are many acrylic aquarium manufacturers that will immediately void your warranty for placing a tank on the foam you have pictured. I think that's enough. I welcome you to do more research. Everyone is free to believe whatever they choose.

The "proper" bottom for an acrylic tank is double 3/4" plywood with screws impact driven and recessed so the screw heads do not make pressure points on the bottom of the tank. If the screws or abnormalities cannot be fixed, then use neoprene as it truly makes an even surface. The foam pictured is wrong regardless if many people do it. Many people in agreeance is a function of power, not truth. Everyone once believed the world is flat, didn't make it any more true. The foam pictured doesn't have enough structural density for larger 300+ gallon tanks, it breaks down over time and compresses.

No need to get your feathers ruffled.
I am a member of reef central as well I know the thread you speak of.
If you read my previous response I said in regarding acrylic some people use foam some do not.
The picture posted is of a frameless glass aquarium which is recommended that you use foam under to avoid pressure points.

And there are other acrylic tank manufacturers that do use foam. No not like the picture posted. they use a high density foam.
For the most part we agree it all depends on the tank and the stand as to weather you should or shouldn't use foam under the aquarium.
It's not a simple No answer. As to foam or not to foam. I welcome you to do more research

 

[Dieselhybrid]

No need to get your feathers ruffled.
I am a member of reef central as well I know the thread you speak of.
If you read my previous response I said in regarding acrylic some people use foam some do not.
The picture posted is of a frameless glass aquarium which is recommended that you use foam under to avoid pressure points.

And there are other acrylic tank manufacturers that do use foam. No not like the picture posted. they use a high density foam.
For the most part we agree it all depends on the tank and the stand as to weather you should or shouldn't use foam under the aquarium.
It's not a simple No answer. As to foam or not to foam

 

[Siddons11]

The high density pink Home Depot sheets have a compressive strength of 15 psi. A tank thats 2ft tall (full of water) only applies about 0.87 psi to it...
According to my calculations, the foam will compress 0.003". (Assuming the Young's modulus will be linear because the foam will reach nowhere near its yield strength)

Point being, if you get the right type of foam board, it doesn't matter if you use it or not. It just helps absorb small stress concentrations that might exist between the stand and acrylic

 

[Jhay3513]

I used the pink foam because there were a few imperfections in the stand that i built. My tank is glass and does have trim so I cut the foam so that it only goes between the wood and plastic trim under the aquarium. I feel like it helped even things out once the weight of the substrate and water were applied