Author Options:

How can I make an aquarium island that's solid and light? Answered

I want to make a large island for my turtles and I want to be able to make it look how ever I want. I need to know what to use for long lasting use in water.



Best Answer 8 years ago

I recently did the same project. my turtle needed a larger dock. I built the basic shape of it out of chunks of styrofoam, u glued the pieces together using "great stuff" expanding foam, comes in a can, you probably know what im talking about. once cured, float it in the pond and apply weight to see how much it's gonna take to sink it. that should give you an idea of how much cement you can put on it. i covered my base with hydraulic cement . i used about 2/3 of a 10lb bucket. i was concerned it wouldnt float because the finished product was so heavy. but it floats at just the right level, guess i got lucky ;) i let it sit outside for about a week, got rained on a couple times, then i gave it another good rinse in the shower before putting it in the pond. but make sure you put a ramp on it, turtles cant climb out of the water onto a vertical edge. i forgot to do that, now i have to make an extension so my turtle can climb up, lol. other than that, it turned out great, hope this helps.

Also, i took pictures of the process and plan to do an instructable with it soon.

Use a terra cotta pot or dish (a plant pot) upside down. Then use polyurethane sealant to glue pebbles/rocks etc. to it to make an island.
The hollow pot would be pretty light, the rocks would make it look and feel more natural (with good grip for the turtles) and you can get potable grade polyurethane sealant that is used on drinking water tanks, so it would be safe for your pets once it is properly cured.
You should be able to get a small tube of sealant at a good hardware store.


8 years ago


If you use cement it needs to cure for a couple of weeks either in water or rinsed several times a day.  There are some salts or minerals (I can't remember which) that need to leach out before you use it.


8 years ago

If you want to be absolutely sure it won't hurt the animals you could buy one or make one out of mesh and then cover it in cement for it to be light and solid.

hope I helped,


Your best compromise that includes "solid", "light" & "probably won't poison your turtles"  is probably to use a wire and foam base covered in cement.

Rocks, sand, cement, plastic; that's all I can think of right now.