# When buying a used tank, how can you tell if its an aquarium or terrarium?



## bobotech

I'm still browsing CL to see if I can find a replacement tank but I want to know how do you tell the difference between a tank designed for water and just a reptile tank?

If I bring my digital calipers, can I tell by the thickness of the glass? If so, how do I know what the proper thickness is for a particular tank size?

I know, annoying questions but I just don't want to get burned by buying the wrong kind of tank.


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## ArtyG

In my experience there is no difference except terrariums come with some sort of screen lid and a way to attach it . Beware of former aquariums that's have been converted to terrariums because they became leakers, those are rare but it happens.


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## Aeten

I think you should be able to tell by the silicone in the corners, that is if its a glass tank. If its an aquarium it will be very thickly on there and extend out of the corners themselves onto the glass walls for about 1/2" or less/more depending on gallonage of the tank. A terrarium won't have heavy duty silconing like that, and if it does it will probably hold water anyway.


Have them fill the tank if you can


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## Alasse

Many reptile tanks look exactly like fishtanks here, just they use a thinner glass as they dont need to hold the water pressure. Thinner glass makes then cheaper to make.


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## SueD

Also on the longer tanks, aquariums will have a center brace. Not sure, but I don't think reptile tanks have these


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## navigator black

If the tank is small, it doesn't matter much. Bigger tanks are a different question.
Odds are, the tank won't be spotless. people clean them up, but the glass isn't usually stripped down to new. Look for the water line in that faint white mineral form. Make sure there is a good top and bottom brace.
If you buy a made for water aquarium that has been used for reptiles long term, the silicone may have dried, so how it was manufactured won't matter...


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## nate2005

Any other tips? I'm thinking of getting a used tank also. It would be a 40g or 50g.


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## ironklad

I have a ~15 gal terrarium that I'm not using right now, which has an approximately 1.5" hole in the bottom panel (for water outlet I guess). This would definitely be something to look for.


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## ArtyG

ironklad said:


> I have a ~15 gal terrarium that I'm not using right now, which has an approximately 1.5" hole in the bottom panel (for water outlet I guess). This would definitely be something to look for.


Yee, and to avoid! Btw, yesterday I bought an immaculate 75 gallon bowfront with stand, lights and a Fluval 305 cannister filter for $100.


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## DigitalBuddha

I would avoid buying any tank that had reptiles in it if you are going to use it for a fish tank. As was already said they can be prone to leaking. Usually they are the same glass in my experience. You will be able to tell if it was previously used for fish or reptiles upon inspection, like navigatorblack said look for the water line. I've also heard bad things about people using soap to clean their tanks and then the soup residue being harmful to the fish so beware.


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## nate2005

the one im going to check out tomorrow housed a snake but looks to be an aquarium.


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## majerah1

I have used tanks that were previously home to reptiles. You just have to clean it well. Against what many others do, I use hot water and dish soap to clean all my tanks. I give them a good wipe down and then a very good rinse. You can also use bleach. Ive a friend who would wash all her tanks out with bleach water and then rinse in 2x dechlored water and then set in the sun for three days.


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## Manafel

Normally I am able to tell if it was used by reptiles by the state of the Silicone. also by how dirty the tank might look. When buying a used tank, one other thing to look for is the condition of the top and bottom braces. If the center brace is broken, or missing, stay far away unless you have the experience or the will to replace the whole top frame.


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## MattSidedish

It really doesn't matter which it was made for. If the joints are siliconed properly, and it won't leak water, it's fine. It may even be good for you to scrape all the silicone off and re-seal it. It won't look perfect, but it will have water in it, so it won't be noticed.


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## WheeledGoat

i must disagree - it would indeed matter what it was made for. aquariums are designed to support the [significant] weight of the water. glass cages are not. and it goes much farther than properly siliconed seams - glass thickness will play an enormous role for structural support.

I did a quick search (not like I know this stuff off the top of my head). The following is from this page. It's a DIY on building your own so it may be a little overbuilt from manufactured aquariums, but at least it'll give ya a ballpark and you can put your calipers to use! 


> Glass Thickness
> Once you have decided on the above you should now decide on the glass thickness for your aquarium. I would recommend the following for various tank sizes (footprint of tank):
> 2 x 1 x 1 = 5mm glass
> 2 x 1 x 1.5 = 6 mm glass
> 2 x 1.5 x 1.5 = 8 mm glass
> 2.5 x 2 x 2 = 10 mm glass
> 3 x1 x 1 = 6 mm glass
> 3 x 1.5 x 1.5 = 8mm glass
> 3 x 2 x 2 = 12 mm glass
> 4 x 1.5 x 1.5 = 10mm glass
> 4 x 2 x 2 = 12 mm glass
> 6 x any size x 2 feet max. = 12 mm glass


Sorry to throw the gauntlet down and disagree with ya, matt - not usually my style - but I really think it unwise to disregard the intended use of the cage. Totally not worth the risk & ensuing disaster!!


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## nate2005

I ended up not buying any. I hope the dollar a gallon sale starts soon


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## MattSidedish

It's cool Goat, but in every case I've seen with terrariums, the glass is thick enough to support possible water usage, especially when you're dealing with terrariums smaller than the typical size of a 30 gallon aquarium. I now realize the sentence about "It really doesn't matter...." was a poor choice of words. I should have included in the requirements, alongside the silicone, that the glass needs to be thick enough. My post was very late at night (at least where I am), and I forgot to add that part.


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## TetraTank

You can always ask the seller if their willing to fill the tank with water to check if It's water tight, some people are honest.

Just never get a tank that has been used for rodents, the silicon will be damaged.

I got my 30gallon set up with everything; tank, hood, plant light, two filters, heater, gravel, decorations, pump, airstone, cleaners, conditioners all for 50$.

I ended up trading an aquarium store for plants for the second hand decoration and getting free fish from someone moving.

Just be patient and keep looking.


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