20 Gallon Tank Reptile tank converted to fish tank?


Good Morning Everyone,

My new Red Cherries have settled in to their new home and their color is coming back, yay!

I bought a 20 gallon tank with a wire cover that had been used for a lizard, I kept my two red eared slider turtles in it for several months, no leaks or problems, only filled it half full.

I would like to use it to set up a guppy tank so I can move my cherries from their 10 gallon to the 20 gallon already cycled tank. This tank does not have the silicone that you see smeared along the inside seams like you do for fish tanks, should I silicone it to make sure it will hold the whole 20 gallons or will it be okay as is? I am thinking I should take it outside on the patio and fill it right up with water and if it does not burst or leak it will be good to go.


Good morning,

I like the idea of testing it outside first. Let it set a while. If it doesn't leak I wouldn't worry about adding the silicone. If it was meant to hold water then hopefully it will be fine

Let's get some more responses on this.

Keep us posted.


My concern would be the original purpose of the tank. If it was meant for aquarium use, I think it's fine - a good scrubbing, and you test for leaks, and you're good to go. However, if it was made for some other purpose, the glass may be too thin to hold water long-term. Just something to think about.


I agree with meenu. I know first hand what happens when you fill a reptile tank up with water. Not something you want to clean up.
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Despite all the warnings I've read, I believe my 20 long was a reptile tank.
I've had it up and running since last summer with no problems.

You'll have to decide if it's worth the risk.


What does it say on the tank itself? Do you see the word Terrarium or Aquarium? If its Terrarium then it's going to be weaker then a Aquarium. I seen a lot of people saying to not do anything larger then a 10g.

It's a good idea to test it outside but I would be too paranoid having that much water in my house in a reptile tank. And honestly, a 20 gallon Aquarium either standard or tall is quite cheap. I would use the reptile tank as emergencey back up.


proudtobefarmgirl, fill it up full in a shady area, and let sit full of water for several days to a week, make sure area it is in (the tank) is cold, heat can be very bad for fhe silicone.

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