Was looking at your build great work! How do you have this much time??? Also, reading the tds meter, looks like a reading of 250 not 52... 52 would be an epic reading from tap water.
1000 Gallon 3D Hole in the wall
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- Thread starter Harlequin Mania
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Looks awesome!!
bairdimusprime
Bill
wow! this is one of the most impressive builds i have ever seen
I ripped through this thread really quick so maybe this has been answered - but am I seeing this correctly: you have no direct support under the very front edge of the tank, besides the aluminum cantilever?
Harlequin Mania
Active Member
Yes, i was feeling you as well having serious doubt about the TDS reading of my TDS meter. Anyway, to be safe all water have to go thru the 5 stage RO/DI filter to remove any silicate ,impurity that the water might have .
Harlequin Mania
Active Member
Thanks guy. Seriously, just when you are talking about this. I really do need to have some power backup for it especially when i am not at home. So far the emergency backup power which i am planning for will consist of solar panel and Deep cycle battery together with a DC converter for us.
So...am I the only one that has a serious concern about the front ~12" of the tank being supported by only a 2" aluminum cantilever?
TriggerThis
Well-Known Member
I don't think it's 12" but it is out there.
It wouldn't have hurt to put three columns or something in the front that look nice...
But as long as it doesn't flex or warp or something it should be fine lol
It wouldn't have hurt to put three columns or something in the front that look nice...
But as long as it doesn't flex or warp or something it should be fine lol
Ok, I don't mean to be a party pooper here but I am an engineer and a tank builder so I have to say my peace. Here is the rendering of the stand. this shows a short cantilever, maybe 6" or so. But this is not the final design...
This, below, is a much larger cantilever. This one spans across the opening and then out another 3-6 inches (hard to tell from the perpsective) but the wall opening looks to be at least 8", then another 4" or so past that. Note that the cantilever spans are also not all continuous from front to back. The main 3 cross spars are double-height, then the outer two are 2 square pieces stacked on top of one another, with the top piece extending out over the wall opening and joining the front member. You can see this in the next pic below this one. The 3 members between the front member and the main bar on the other side of the wall connect only on the interior. It also does not appear that the cantilever spans are supported by the wall opening, which also appears to be finished tile, not a structural wall member that could be directly anchored to.
Outer bar is a double-stacked square bar, only one goes out over the wall...
The entire partial/fractional weight of the front 12" of this tank is virtually unsupported.
That is a potentially huge amount of stress that is focused on the bottom panel joint and walls along the front edge and front part of the side edges. Acrylic tanks, unless they are overbuilt significantly, just aren't supposed to be floating on the edges. I'm not saying that the tank is going to fail for sure, but I sure as heck would never have done this without sign-off by the tank manufacturer and getting a structural engineer involved. I work for a firm that does forensic engineering investigations and I'm willing to bet that if I run this by my structural engineer he would download in his pants.
This, below, is a much larger cantilever. This one spans across the opening and then out another 3-6 inches (hard to tell from the perpsective) but the wall opening looks to be at least 8", then another 4" or so past that. Note that the cantilever spans are also not all continuous from front to back. The main 3 cross spars are double-height, then the outer two are 2 square pieces stacked on top of one another, with the top piece extending out over the wall opening and joining the front member. You can see this in the next pic below this one. The 3 members between the front member and the main bar on the other side of the wall connect only on the interior. It also does not appear that the cantilever spans are supported by the wall opening, which also appears to be finished tile, not a structural wall member that could be directly anchored to.
Outer bar is a double-stacked square bar, only one goes out over the wall...
The entire partial/fractional weight of the front 12" of this tank is virtually unsupported.
That is a potentially huge amount of stress that is focused on the bottom panel joint and walls along the front edge and front part of the side edges. Acrylic tanks, unless they are overbuilt significantly, just aren't supposed to be floating on the edges. I'm not saying that the tank is going to fail for sure, but I sure as heck would never have done this without sign-off by the tank manufacturer and getting a structural engineer involved. I work for a firm that does forensic engineering investigations and I'm willing to bet that if I run this by my structural engineer he would download in his pants.
Arrivalanche
New Member
It's David Blain's tank. Lol.
Harlequin Mania
Active Member
Thanks for rising this concern up, and this concern was certainly one of mine too when someone spoke to me about it. I didnt update in my tank thread in detail of the modification / adjustment that had been made by my system builder when i rise this concern over to them, but i guess it would help for other planing for such alu profile stand in future what to look out for.
The adjustment we did was ;
1) All corner edge of the alu profile has been reinforce with bracket to prevent against side linear forces.
2) As the initial plan was for the front alu profile to sit on the concrete wall adding as an additional vertical support for the front, but it turn out that the stand was made too high. As such additional support base using wood has been placed in between the gap in between the profile and the concrete wall.
3) The alu Profile stand has also been secure to the concrete wall using bracket as an additional measures against side linear forces.
maybe i will snap some photos later on... I was told that the profile has been widely use as a heavy duty racking that support weight heavier than my tank, and i guess it is still pretty new in this hobby.
Harlequin Mania
Active Member
Most of the profile used was 40x20 .
It's not the stand that I'm worried about failing. There is no doubt that the modular aluminum frame stand provides adequate strength to support the weight of the tank - as you mention, the builder stated that it is used to support much heavier loads.
The problem is the tank. Acrylic tanks are supposed to have 100% support under the bottom of the tank. If you look at nearly every "large" acrylic tank, the footprint of the stand matches the footprint of the tank. There are many reasons for this. While I cannot claim to be the "expert" on this, I do build tanks and other acrylic products, so I have taken it upon myself to research things like this (so anyone else, feel free to correct me). But back to what I was saying, the issue is that the acrylic bottom of the tank, and more specifically the joint between the walls and the bottom of the tank (the walls are bonded to the bottom, i.e. the tank is assembled by putting all 4 walls together then bonding the top & bottom on last) so this joint has to be able to withstand a certain hydraulic (water) pressure at the given depth of the tank. It is this pressure that mandates the required wall thickness so that the joint / walls are strong enough to withstand the constant pressure for year and years.
What is not figured into that calculation (for a standard tank) is the additional pressure of the contents of the tank (the water column above the bottom of the tank) pushing downward only along the front edge of the tank and causing a minute deflection of that joint that is not possible across the rest of the bottom/side joints (because they are supported). Think of it like a diving board. You stand on the middle of the diving board, it doesn't deflect. If you stand on the end, it deflects downward. Now bond some vertical walls to the sides of the diving board, and it will not deflect as much, but it will still deflect. In an acrylic aquarium, deflection is bad. You want to avoid it at all costs. So the original plan of having the stand in contact with the wall (good that it is concrete!!) was good, but in reality, no one builds a stand dead-on perfect, so you were probably going to have to have some shims in there anyways
so the wood block added will very greatly help the situation, and I breathe a small sigh of relief. If the front edge of the tank only extends out past the wood block support a few inches, then that's better than 12". But I would just keep an eye on that front bottom joint.If it were me, I might even go as far as taking a set of high-res pictures of the joint in sections, once every few months, and comparing them to look for possible signs of hairline fractures. I maintained a 120 acrylic tank that, as it turns out, was only supported on the ends and 2 square steel tubes along the front & back (and the one in the front was 1/8" low).
The base between that was 3/4" unsupported particle board (so it bowed badly down). It developed a fracture through the bottom panel along the plane of the inside of the front panel (cracked through the bottom panel). By the time I noticed it, the 1/4" thick bottom panel had fractured 3/4 of the way through - so there was 1/16" between the tank contents and disaster. That fracture showed up in pictures very well...
Harlequin Mania
Active Member
It's not the stand that I'm worried about failing. There is no doubt that the modular aluminum frame stand provides adequate strength to support the weight of the tank - as you mention, the builder stated that it is used to support much heavier loads.
The problem is the tank. Acrylic tanks are supposed to have 100% support under the bottom of the tank. If you look at nearly every "large" acrylic tank, the footprint of the stand matches the footprint of the tank. There are many reasons for this. While I cannot claim to be the "expert" on this, I do build tanks and other acrylic products, so I have taken it upon myself to research things like this (so anyone else, feel free to correct me). But back to what I was saying, the issue is that the acrylic bottom of the tank, and more specifically the joint between the walls and the bottom of the tank (the walls are bonded to the bottom, i.e. the tank is assembled by putting all 4 walls together then bonding the top & bottom on last) so this joint has to be able to withstand a certain hydraulic (water) pressure at the given depth of the tank. It is this pressure that mandates the required wall thickness so that the joint / walls are strong enough to withstand the constant pressure for year and years.
What is not figured into that calculation (for a standard tank) is the additional pressure of the contents of the tank (the water column above the bottom of the tank) pushing downward only along the front edge of the tank and causing a minute deflection of that joint that is not possible across the rest of the bottom/side joints (because they are supported). Think of it like a diving board. You stand on the middle of the diving board, it doesn't deflect. If you stand on the end, it deflects downward. Now bond some vertical walls to the sides of the diving board, and it will not deflect as much, but it will still deflect. In an acrylic aquarium, deflection is bad. You want to avoid it at all costs. So the original plan of having the stand in contact with the wall (good that it is concrete!!) was good, but in reality, no one builds a stand dead-on perfect, so you were probably going to have to have some shims in there anyways
If it were me, I might even go as far as taking a set of high-res pictures of the joint in sections, once every few months, and comparing them to look for possible signs of hairline fractures. I maintained a 120 acrylic tank that, as it turns out, was only supported on the ends and 2 square steel tubes along the front & back (and the one in the front was 1/8" low).
The base between that was 3/4" unsupported particle board (so it bowed badly down). It developed a fracture through the bottom panel along the plane of the inside of the front panel (cracked through the bottom panel). By the time I noticed it, the 1/4" thick bottom panel had fractured 3/4 of the way through - so there was 1/16" between the tank contents and disaster. That fracture showed up in pictures very well...
Hi turbo,
Thanks for taking the time and sharing your detail insight on it. I can clearly understand what you mean on the front beam support, and yes in order to sleep well day after day this has to be seriously look into.
My next plan was to do a major 90% water change in order to be able to shift the whole stand out and reinforce with more legs and support.
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