Polymorph plastic is an exciting new compound in the aquarium hobby which has a wide range of versatile uses. This material is a non toxic polyester which has a low melting point of about 140F, but is workable by hand until it hardens at to a solid at room temperature.
Polymorph plastic is currently being offered to the aquarium hobby by many different companies including Grotech and Fauna Marin’s Aquascape Fix, and many others. The material is commonly available from DIY suppliers for $35 per Kilogram, but naturally that which is packaged for the hobby carries a premium.

What makes polymorph plastic so interesting to the aquarium hobby is that it can be sticky like super glue, yet it can be worked by hand like epoxy. The qualities of polymorph plastic really changes depending on its temperature, being quite sticky and soft at its hottest, but becoming hard and strong when it cools.
Unlike epoxy, polymorph plastic actually expands as it cools, whereas epoxy tends to shrink, making it much easier to create a good strong bond with this type of plastic. Better yet, polymorph plastic is much less expensive than epoxy and it can be reused by simply heating it back up to 140 degrees with hot, nearly boiling water, and working it back into whatever you want.

The first obvious application for polymorph plastic in the aquarium hobby is to secure larger pieces of corals or rocks in the aquascape. We’ve actually tested it out in this latter application and found it to be a very strong securing agent for holding up precarious placed rocks. While the polymorph plastic does the job of holding rocks up, its bright white color when cooled stands out in the display and since the material is smooth, there’s been very little overgrowth of algae to hide its presence.
We’ve actually experimented at camouflaging the moldable plastic by incorporating some of dark sand which greatly altered the color and texture of the material. However this probably reduces the adhesive property of the polymorph plastic, but it should make it easier for biofouling to occur to conceal it in the aquascape over time.

But the uses for polymorph plastic goes well beyond simply fastening corals and rocks. The moldable plastic can be shaped into anything you want, you could make elaborate frag plugs a-la Reefgen, and you could probably create a temporary seal of minor cracks in plumbing or pump volutes.
The possibilities for polymorph plastic in aquariums is only really limited by your imagination. Special pump mounts, home-made frag racks, line holders, probe holders, and even homemade aspirator valves or needle wheels can be created with this versatile new material. We’re just beginning to imagine what is possible with polymorph plastic, but we’ll be keeping plenty on hand for the next time we need a special fix for our aquariums.
There’s a whole Pinterest page showing oodles of uses for Polymorph plastic, what can you think to do with it for our aquariums? Let us know what you would do with it in the comments.