Opinions on "flexy rack" stand idea

[kgk]

I am in the process of planning my first tank in 6 years. My current thinking is to use a 58 gallon Oceanic reef-ready tank (with pre-made overflow to simplify my life), and build a custom stand and sump/refugium setup. Right now I am pondering stand designs. One concept I had is a take-off of something home theater geeks have been doing for years. It's called a "flexy rack". Basically, you use wood to make the shelves, and you drill holes in the shelves for threaded metal rods. You use big nuts on the threaded rods to lock the shelves in to place. The beauty of this is that is simple to build, eminently flexible, and low-cost. I attached a picture of a flexy rack so you can get a visual idea of the concept.

I am having a hard time thoroughly convincing myself that a stand built in this manner will hold the weight of the tank, full of water, sand and liverock. Opinions would be greatly valued.

Thanks.

 

[ReefTECK]

no way, the 58 gallon oceanic tank is one of the heaviest "small" tanks I have ever lifted. It's constructed with 3/8" glass. Add water ontop of that and it would be a total disaster.

 

[shaneh]

i'd just build a stand out of wood i don't think i would trust it. You don't want your tank to be "flexy" and have a large mess. if you build and spend the money now it will save you in the long run.

 

[uncleof6]

Well if you have no confidence in this design, why consider it? The tank needs solid support under the four corners. This style of stand is not going to provide that.

Jim

 

[kgk]

Well if you have no confidence in this design, why consider it? The tank needs solid support under the four corners. This style of stand is not going to provide that.

Jim

I am pretty sure it will work. I don't know if people have ever tried this or not, though. The architecture of the stand is appealing because it is cheap, flexible and open. I can easily put shelves at any height, and make this thing any size I want.

For instance, what I had in mind is bigger than what is in the picture. 6 "legs" - one in each corner, and 2 in the middle. It would have 3 levels of shelves, with 2 20 gallon tanks acting as sump/refugium. The middle shelf would only extend 1/2 way across. This would give room above to grow mangroves in the bottom 20 gallon tank.

The metal rods also take up less space than wood, and give a better view of what's going on in the lower tanks.

 

[kgk]

no way, the 58 gallon oceanic tank is one of the heaviest "small" tanks I have ever lifted. It's constructed with 3/8" glass. Add water ontop of that and it would be a total disaster.

Thanks for that. Do you have a recommendation for a better tank or size? I am thinking in the 50-65 gallon range. I have 5' of wall space to work with so a 4' tank would be fine.

 

[kgk]

i'd just build a stand out of wood i don't think i would trust it. You don't want your tank to be "flexy" and have a large mess. if you build and spend the money now it will save you in the long run.

"Flexy" does not refer to anything being physically flexible. It refers to the flexibility of the design.

Cost is not the primary concern here, flexiblity & looks is. I can do exactly what I want, simply, with this design. Wood bracing is much more cumbersome.

 

[uncleof6]

I am pretty sure it will work. I don't know if people have ever tried this or not, though. The architecture of the stand is appealing because it is cheap, flexible and open. I can easily put shelves at any height, and make this thing any size I want.

For instance, what I had in mind is bigger than what is in the picture. 6 "legs" - one in each corner, and 2 in the middle. It would have 3 levels of shelves, with 2 20 gallon tanks acting as sump/refugium. The middle shelf would only extend 1/2 way across. This would give room above to grow mangroves in the bottom 20 gallon tank.

The metal rods also take up less space than wood, and give a better view of what's going on in the lower tanks.

There needs to be direct vertical support under the corners of the tank. NOT outside the perimeter of the tank: under the corners of the tank. The support with this stand type, will be the wood shelf, not the uprights. It is not going to be a rigid shelf under the tank, the wood will deflect. I give this idea: :thumbdown:thumbdown

FWIW,

Jim

 

[hllywd]

Can you say.....


SPLATTTT!!!!

In other words I don't think it's a good idea!
Tim

 

[hyperfocal]

Jim, what if the top shelf was sized to match the tank better and was secured from the bottom with a threaded collet (rather than drilled through and bolted)? That'd provide the direct support under the corners of the tank but still stay within the style of the original design. You'd sure want to be sure all those bolts are tight and stay that way though.

 

[kgk]

There needs to be direct vertical support under the corners of the tank. NOT outside the perimeter of the tank: under the corners of the tank. The support with this stand type, will be the wood shelf, not the uprights. It is not going to be a rigid shelf under the tank, the wood will deflect. I give this idea: :thumbdown:thumbdown

FWIW,

Jim

OK, I understand what you were getting at. It would be possible to put the support directly under the corners of the tank, but that would complicate the build somewhat. Good feedback, thanks.

 

[kgk]

Can you say.....


SPLATTTT!!!!

In other words I don't think it's a good idea!
Tim

I have a friend who built one of these racks, and it houses a 250 pound 36" CRT TV on the top shelf. It certainly seems reasonable that you could build one to hold a 500 pound tank if you choose components well.

 

[jefft72]

I built one of these stand designs years ago for home theater use. I did not put a hole all the way through the top shelf, so it was supported on the corners underneath by a large washer/nut combo.

I like the design and it may work out well, but I would definitely use larger hardware for sure. I would say 5/8" or 3/4" all thread, nuts, and washers to start. You may reevaluate the basic design so that the overall stand is perhaps over built.

 

[kgk]

Jim, what if the top shelf was sized to match the tank better and was secured from the bottom with a threaded collet (rather than drilled through and bolted)? That'd provide the direct support under the corners of the tank but still stay within the style of the original design. You'd sure want to be sure all those bolts are tight and stay that way though.

This is what I had in mind too. It would look better - nothing protruding from the top board. It would be slightly more work to build.

To be honest, I am rapidly moving away from this idea, mainly because I have 2 young kids, and I should probably design something with a way to keep them out of the sump.

I do believe you could make this work, but you certainly would have to put some thought into it, and it gets progressively harder the bigger the tanks get. I was thinking about a 90, then I got smaller due to weight ... if I give up on this stand, then it simplifies things. I would probably give up on growing Mangroves, too though - I had wanted those out so that they are part of the display. Tucking them under a stand behind closed doors removes some of the draw of having a mangrove grow in the sump/refugium.

 

[der_wille_zur_macht]

I have a friend who built one of these racks, and it houses a 250 pound 36" CRT TV on the top shelf. It certainly seems reasonable that you could build one to hold a 500 pound tank if you choose components well.

The difference is this: If a 250lb TV causes a 1/8" deflection in the top of the stand, nothing bad happens. If a fish tank causes a 1/8" deflection in the top of the stand, it's likely to cause the tank to fail.

 

[kgk]

The difference is this: If a 250lb TV causes a 1/8" deflection in the top of the stand, nothing bad happens. If a fish tank causes a 1/8" deflection in the top of the stand, it's likely to cause the tank to fail.

Thank you. I had not considered this. I was thinking of the stand failing, not the tank.
His stand did not visibly deflect at all but I see the risk here now.

 

[hllywd]

OK several things;
Salt water spills, salt creep etc.. are not going to be very friendly to regular all-thread unless you like the rusted look. You could probably clear coat it once everything is assembled but eventually it's going to rust.
Structurally, as long as you're transmitting the load directly through the four corners, and directly to the floor you might be ok, remember with 3/4" rod that's close to 170psi, make sure your floor is up to that for the long run. Lastly, it's not that I don't like the look of that idea, but it's going to need some diagonal bracing. Add 500+ lbs on the top and I think it's going to sway quite a bit as is. Those are my more constructive thoughts!

Tim

 

[ReefTECK]

I think what you're hearing is a unanimous "don't do it" from the community.

I don't doubt that this thing could withstand the compressional force, but rather the angular force of 500lbs I don't believe it will (ie; any flex in the floor, dog/child running into the stand, you bumping into the tank, minor earthquake etc.) I think the side force on the stand will cause it to fail period.

let alone other supportive considerations to keep the glass from "flexing"

If anything consider using acylic to design the tank itself, to save on weight.

 

[stugray]

Whats with the negative attitude?

"no way, the 58 gallon oceanic tank is one of the heaviest "small" tanks I have ever lifted. It's constructed with 3/8" glass. Add water ontop of that and it would be a total disaster."

8.4 lbs per gallon = ~500 lbs.
Thats ~125 lbs per corner
We are talking about Steel all-thread, anyone look up the compression strength of Steel all thread?

"Well if you have no confidence in this design, why consider it? The tank needs solid support under the four corners. This style of stand is not going to provide that."

See above

"There needs to be direct vertical support under the corners of the tank. NOT outside the perimeter of the tank"

See above

"Can you say.....

SPLATTTT!!!!

In other words I don't think it's a good idea!
Tim "






Sorry that I have to disagree, BUT:

As long as the shelf that supports the tank is thick enough to NOT DEFLECT under a load, I dont see why it is a problem.

Make sure that the piece that supports the tank is PERFECTLY flat ( doesnt need to be perfectly level), then WHY would it not work?
I would double up some 3/4" Plywood, paint it black and it should be fine.

I might worry about someone bumping into it and causing a "racking motion", but that can be solved with some diagonal braces on the back & sides.


Stu

 

[kgk]

I think what you're hearing is a unanimous "don't do it" from the community.

Yeah, I gave up on the idea about 3 in the afternoon today.

I don't doubt that this thing could withstand the compressional force, but rather the angular force of 500lbs I don't believe it will (ie; any flex in the floor, dog/child running into the stand, you bumping into the tank, minor earthquake etc.) I think the side force on the stand will cause it to fail period.

let alone other supportive considerations to keep the glass from "flexing"

If anything consider using acylic to design the tank itself, to save on weight.

Agreed, it's simply not going to work without more structure, size, cost, etc, than I am willing to put into it.

I have access to a machine shop and could custom fabricate some cool stuff, but that is simply more work than I'm willing to undertake for this project, especially for a Flexy sort of design.

I am probably going to simply buy a pre-made stand. I am sure that would make my wife happy. I will spend my time on other parts of the project instead.