Never buy a very large glass aquarium.

I just watched some guy give away 20g worth of busted 400 gallon reef tank (and protein skimmer taller than you) that just exploded. Then,you can watch an older vid of Lucas Bretz's 240 gallon glass tank- rupture.
Go acrylic on 100 gallons or more. They never leak and that more than makes for having the usual complaints of scratches. Even those can be buffed out one day. You can't even do that as a hobbyist for a glass tank with deep scratches.
My 240 is about 40 years old and it's been set up crooked and worse over the years- I once dropped it empty from knee high. Go acrylic.
Oh,and notice how many public aquaria go acrylic now. Even they are afraid of glass...even as just a front pane, let alone all glass.

My LFS’ Monster Tank is acrylic, super sturdy. The logic makes sense.

I also assume it’s generally cheaper?

They are..but not exactly a huge discount...but that they cost less is a great incentive.
I once talked to an expert on building aquariums and he said that even if my 240 sprang a leak? I could use a glue that sets underwater and isnt toxic in that small amounts to fish. He made it sound like repairing the largest acrylic tank isn't a tough act.
Once a large glass tank bust a seam? The party is over.

I would also like to buy an acrylic tank. Its not widely available to buy from stores in here in the uk. Well at least the places i normally visit. It all makes sense to go acrylic with what you guys have mentioned. Maybe my next one will be an acrylic custom built tank.

The problem with big tanks is due to poor quality silicon and not giving the silicon enough time to dry. It happens to small tanks as well, someone uses cheap crap quality silicon from China and it degrades quickly and the tank leaks. Bigger tanks have more pressure and when the seals go, there is more pressure pushing the glass out and the entire tank goes.

The glass needs to be clean and free of grease, oil or anything else before the silicon is applied, otherwise it won't adhere to the glass.

Large aquariums need at least 1 week for the silicon to cure completely, and that is in warm dry conditions. It takes longer on cool or damp conditions.

Make sure they use a decent quality silicon that is specifically designed for aquariums.

Get a decent tank maker to build it and put a warranty on it. If you are paying $5000 for an aquarium, it should have a warranty.

Make sure your home insurance covers water damage from the fish tank going bang.

Today I have some problem with this particular tank and just learn my biggest lesson: NEVER BOUGHT A CHEAP TANK

I’ve been looking for a cheap rimless tank for my Iwagumi and found a fish store that can make custom rimless tank
(24”x12”x15”) for only 750THB ($23.90)

Today the thing arrived and look at their work!
The glass doesn’t even lined up and doesn’t even touch each other, side glass are taller, silicon is everywhere and there is chips on he glass, no wonder why it’s this cheap for rimless.

I can’t even return them and I don’t know if it safe to use

Barry Tetra said:

Today I have some problem with this particular tank and just learn my biggest lesson: NEVER BOUGHT A CHEAP TANK

I’ve been looking for a cheap rimless tank for my Iwagumi and found a fish store that can make custom rimless tank
(24”x12”x15”) for only 750THB ($23.90)

Today the thing arrived and look at their work!
The glass doesn’t even lined up and doesn’t even touch each other, side glass are taller, silicon is everywhere and there is chips on he glass, no wonder why it’s this cheap for rimless.

I can’t even return them and I don’t know if it safe to use




View attachment 134347View attachment 134348View attachment 134349

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Wow! That is some shoddy workmanship.
You could do better yourself.

I wouldn't be putting water in that personally.

I'd consider stripping it apart and sealing it myself if it can't be returned, as it's 'custom made'.

Barry Tetra said:

I’ve been looking for a cheap rimless tank for my Iwagumi and found a fish store that can make custom rimless tank
(24”x12”x15”) for only 750THB ($23.90)

Today the thing arrived and look at their work!
The glass doesn’t even lined up and doesn’t even touch each other, side glass are taller, silicon is everywhere and there is chips on he glass, no wonder why it’s this cheap for rimless.

I can’t even return them and I don’t know if it safe to use

Click to expand...

All tanks should be rimless at that size. Just make it out of 6mm thick glass and your good to go.

It would appear the person who measured the glass, was thinking of using the glass on the outside of the base instead of on top of it. Someone wasn't thinking when they did that. And the silicon looks opaque/ white, which is normally an indication of old silicon.

How does the silicon feel?
Is it hard or firm but slightly squishy?

Take the tank outside and fill it up with water. Leave it for a week and see if it holds.

Colin_T said:

How does the silicon feel?
Is it hard or firm but slightly squishy?

Click to expand...

Yep, like that.

Fishfaced said:

Wow! That is some shoddy workmanship.
You could do better yourself.

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Right?! I feel really mad when this thing arrived.

Another advantage with acrylic over glass is that their empty weight is MUCH less than glass.

Weird hypothetical question here, but if you were to have an acrylic tank in an upstairs room, would it put less strain on the floor than having a glass tank of the same size?

PlasticGalaxy said:

Weird hypothetical question here, but if you were to have an acrylic tank in an upstairs room, would it put less strain on the floor than having a glass tank of the same size?

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Less weight = less "strain", but how significant of a difference I'm not sure....the larger the tank, the larger the difference, is my guess ?

Slaphppy7 said:

Less weight = less "strain", but how significant of a difference I'm not sure....the larger the tank, the larger the difference, is my guess ?

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Hmm... Only wondering since I'm going to be cheeky and ask for a 5-6ft tank for my birthday, but my parents have already (understandably) voiced their concerns about the floor caving in lol. I wonder if an acrylic tank would put less strain on the floor than a glass tank.

Colin_T said:

All tanks should be rimless at that size. Just make it out of 6mm thick glass and your good to go.

It would appear the person who measured the glass, was thinking of using the glass on the outside of the base instead of on top of it. Someone wasn't thinking when they did that. And the silicon looks opaque/ white, which is normally an indication of old silicon.

How does the silicon feel?
Is it hard or firm but slightly squishy?

Take the tank outside and fill it up with water. Leave it for a week and see if it holds

Click to expand...

I've never heard that. Why should tanks be rimless over a certain size?
Thanks.

Stan510 said:

I just watched some guy give away 20g worth of busted 400 gallon reef tank (and protein skimmer taller than you) that just exploded. Then,you can watch an older vid of Lucas Bretz's 240 gallon glass tank- rupture.
Go acrylic on 100 gallons or more. They never leak and that more than makes for having the usual complaints of scratches. Even those can be buffed out one day. You can't even do that as a hobbyist for a glass tank with deep scratches.
My 240 is about 40 years old and it's been set up crooked and worse over the years- I once dropped it empty from knee high. Go acrylic.
Oh,and notice how many public aquaria go acrylic now. Even they are afraid of glass...even as just a front pane, let alone all glass.

Click to expand...

And I imagine with acrylic it should be possible to put screws or pins into the joints to supplement the silicon.