Slight bending of front glass due to water pressure common?

[PeterGwee]

Was wondering if the tanks that you guys own have this behaviour? About 1-3mm of bending found due to the water pressure as well as the substrate?

[vinz]

Weight of water. Substrate is too low to make an obvious difference. My 1m tank shows it too.

[timebomb]

If your glass is bending, then I would advise you to think about stripping down the whole tank. The last time I saw a tank with a bent glass, the tank eventually gave way. I'm not going to name the fish shop as I don't want to embarrass the owner. But it was a 5 feet tank and the thing gave way when the shop was closed. The owner didn't know until the neighbour shop called him and said that water was spilling out from under his front door. When he went back to the shop, it was like a nightmare come true. Fish were jumping all over the shop, substrate was everywhere and the electrical wiring was all shorted.

As far as I know, the glass in our tanks shouldn't bend. If they do, the tank is likely to give way one day. I have a friend who's an expert with glass and he explained this to me once:

Glass will always bend. Actually, flex will be the correct word. That's one of their natural properties. The bigger the piece of glass, the more likely it is to flex. It doesn't matter how thick it is although thicker glass will flex less than thin glass. All glass can take flexing to a certain point. Beyond that point, the glass will crack. That's the reason why fish tanks usually have bracing. The idea of the bracing is not to hold the tank together but to prevent the glass from flexing. In my big tank, I have braces of all 4 sides of the tank. I know many hobbyists don't like the idea of bracing as they are obstructive when doing maintenance work in the tanks. Fish shop owners usually won't care less too as it's no longer their responsibility once the tank is sold.

If you have small children at home, it can be very dangerous for them when the tank gives way. Do not take risks.

Loh K L

[Allen_1971]

timebomb,

u have pm.

[vinz]

What about installing bracing without stripping down the whole tank... i.e. transfer fishes out, reduce water till the glass is straight, install bracing, wait till it sets, put back water, put back fishes.

[timebomb]

What about installing bracing without stripping down the whole tank
..............

I'm not sure but I think it should work. Actually, Edward is the expert. Maybe you should call him and ask him for his advice. His handphone number is 97237783. But take note that Edward wasn't the one who told me about the glass flexing. That came from another friend who makes fish tanks for a living. Don't worry about bothering Edward when you call him. As far as I know, Edward is one of the most helpful persons I know.

In the meantime, keep your son away from the tank.

Loh K L

[Nicky]

Talking about the 'bending glass'.. If you visit the ever-popular fish farm in West Part of Singapore, you will notice that the one display tank on the outside has such a bend-front-glass-panel that it is scary.

You have to look at the glass-pc from the side to notice it.

[timebomb]

Speaking of scary, that was what I felt too when I saw the fish tank that eventually gave way. When I pointed it out to the shop owner, he said it was normal and there was nothing to be worried about. He was, in fact, so confident that the tank won't give way he actually jumped and hanged on to the front of the tank for a few seconds to prove how strong the tank was.

When the tank eventually gave way, it wasn't him who told me the story. That came from another friend who knew what happened. The horror stories are the ones you won't usually hear from fish shop owners. If I'm a fish shop owner too, the last thing I would want to tell you is that one of my fish tanks gave way. That would really be bad for business, don't you think?

Loh K L

[PeterGwee]

Oh dear....speaking of the tank..it is right in front of my bed....cannot imagine it gave way! Timebomb, you mean no matter what the glass should not bend even if it is just a little? The weight of the water and the substrate would surely act on the glass itself..wouldn't slight bending occur?

[loupgarou]

all those nisso/gex 5 plan tank (2ft type) all flex, are those safe?

[Nicky]

Related to this 'scary tales' I have another one to share..

I am not using Tampered glass tank and I always thought like 'blue-glass-tank' sold by LH shop, these are 'gimmick'.

I heard a story from a reliable source that when a big tank (made of tampered glass) cracks, it will break into small bean-size glass beads.. and with the water pressure behind the glass before it breaks, the bean-size glass beads will actually be strong enough to embed itself into walls (very much like the picture of a play-card 'stuck' into a tree-truck during a typhoon). The source told me he knew of someone whose tank cracked in this way in the office over the weekend. Lucky it was during the weekend..

[vinz]

Tempered glass... not tampered.

Tampered means a whole different thing... and it would explain why the glass broke!

[bclee]

Tempered glass is safer than normal glass.

First of all tempered glass is harder and take more stress to break it.

Secondly, when tempered glass break, it shatters into small beads that are relatively blunt compared to a normal glass. When a normal glass break, it will break into large & sharp pieces. Imagine a large piece of sharp broken glass about 3kg landing on your foot...[]

Although glass beads from the tempered glass can be damaging, it is still safer compared to a normal glass.

BC

[PeterGwee]

Maybe should custom made a tank which is 12mm all round and with bracing on 4 corners for maximum safety huh?

[Allen_1971]

actually if you want your bracings to be strong you need them in the centre of your tank where most of the flexing is likely to occur... in longer tanks you might need more than 1 centre brace.

[timebomb]

Maybe should custom made a tank which is 12mm all round and with bracing on 4 corners for maximum safety huh?
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Peter, my tank was made several years ago. It's 50"(L) X 26"(W) X 24"(H). The glass is 10 mm thick. I have bracing all round and the glass used as bracing is 12 mm in thickness. My glass never bends. I check every now and then by looking at it from the side and the front piece of glass is straight as an arrow.

Now that you have noticed a bend in yours, I would urge you to do something about it. Tanks giving way are horror stories one hears of every now and then. You don't want it to happen to your tank, not when it's right in front of your bed. When the glass in a tank cracks, it makes a noise like an explosion. No kidding hor. I have a 2 and a half feet tank which cracked several years ago. But strangely, although it made a loud noise when it cracked, the tank didn't give way. The water started bursting out through the crack, that's all. But bear in mind that was a relatively small tank. If it's anything around a 4 footer, I don't think the glass would have held.

The planted tank hobby is relatively new here. In the old days, people usually have bare tanks. A bare tank would weigh a lot less than a planted tank of the same size because there's no gravel. I think that's why there were fewer stories of tanks giving way in the old days. In fact, it was standard practice to use 6 mm glass even for a 4 feet tank. Even when hobbyists have gravel in their tanks, the depth of their substrate is a lot lower than ours. I remember calculating that the gravel alone in my tank weighs about 100 kilograms.

Loupgarou, I'm not sure what are those tanks you mentioned but if they are only 2 feet in length, you have nothing to worry about. Like I said earlier, the bigger the piece of glass, the more it flexes. It's only people with 4 feet tanks or bigger who have to be careful.

Loh K L

[timebomb]

actually if you want your bracings to be strong you need them in the centre of your tank where most of the flexing is likely to occur... in longer tanks you might need more than 1 centre brace.

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Centre braces are not meant to prevent the glass from flexing. They are used to hold the tank together. Only those braces that run along the whole length of the glass can prevent flexing.

Loh K L

[PeterGwee]

Timebomb..thanks for the info...but mine is actually a 2 feet tank...any cause for concern? I did not really measure my tank thickness until recently...wah..only 5mm...no wonder so cheap.. ..Anyway, I went to a lfs and ask the ppl there for a custom made tank.

Ideal tank in mind is
60cm x 30cm x 40cm (Due to space constraint so cannot get big tank.. )
12-15mm thickness
bracings all round..
Price..still in progress.

[timebomb]

Timebomb..thanks for the info...but mine is actually a 2 feet tank...
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Alamak, 2 feet tank, nothing to worry lah. But if your glass is only 5 mm thick, that would explain why it's bending.

As for the tank you have in mind, 12 mm thickness would be overkill. 10 mm thick would be more than enough. In small tanks, you also don't need bracing on all sides. Just brace the tank along the widths would be fine.

Loh K L

[PeterGwee]

Thanks thanks timebomb...overkilling the tank is better than killing me! LOL []