Thrive Hexagon Bioactive Vivarium Build

I own three Thrive hexagon terrariums and use them for my mourning geckos. After I reviewed the cage, many of you asked how I would build one out for a crested gecko. This is the full build.

Step 1: a silicone base layer

Coat the back in silicone first, to give the backdrop a solid color under the foam. Let it dry completely; I left mine a couple of days.

Step 2: foam and fixed decorations

Great Stuff, or any foam gap filler from a hardware store, forms the texture of the background and glues in anything you want fixed for good. I used a "lounging log", sticks tied with bendable wire, as a basking ledge about two thirds of the way up, plus a piece of grapevine lower down as a perch.

• Wear gloves. The foam is messy and very sticky.
• Go easy on the amount. It expands a lot as it dries.
• Lay the cage on its back, hold each piece in place and build foam around it.

Let it dry overnight.

Step 3: silicone and soil

Cover all visible foam with the same silicone. While it is wet, pour reptile soil over it and pat it down gently. When the silicone dries, the soil sticks and you get an earthy, textured background. With as much as I use, this can take a few days to dry.

Step 4: substrate

A bioactive build normally starts with a drainage layer: clay balls under a screen, so extra water drips into a gap below the soil. This tank has little depth for soil, so I skipped it. You can, but be careful not to overwater, or the bottom of the soil sits soaking and gets gross.

I used 19 L (20 qt) of Josh's Frogs BioBedding, poured water in to get it really wet, and packed it down firmly.

Step 5: plants and decor

• First plant: dig about halfway down, so the roots have room to grow, and pack soil tightly around it so it stays up when a gecko climbs on it.
• Pothos: dig a line, lay the roots in and cover them. It grows fast, but it is easy to clip and the cuttings can go into other cages.
• Cork bark: a large piece behind the ledge for climbing and hiding.
• Mossy vine: buried at one end and wrapped around the top of the cork bark to use the vertical space.
• Food dish: a Pangea magnetic food dish on the side wall.
• Moss: soaked moss in the open spots. It looks good and helps hold humidity.

Two things you still need

1. A UVB light on top. The plants need it, or they die.
2. A cleaner crew. Small insects break down waste, spilled food and mold on the moss. I keep a springtail colony in a large Repashy jar with charcoal and scoop some into the tank, where they breed and live.

Who lives here

This build suits a crested gecko, but this one went to a leachianus gecko I bought for my wife. Leachianus reach about 36 cm (14 in) and 300 g, against about 15 cm (6 in) and 60 g for a crested gecko, so he will likely outgrow it in about a year and a half.