Is PETG Safe for Aquariums? Aquarium Safe Plastic Explained

Yes, PETG is safe to use in an aquarium. It is the plastic most 3D printed aquarium parts are made from, and aquarium keepers have used it submerged for years without reported problems tied to the material itself.

This guide covers what the aquarium hobby already says about PETG, how it compares to PLA and ABS, why we skip dyed and carbon fiber filament on tank parts, and what we can and cannot promise about your fish or shrimp.

What the aquarium hobby has already decided about PETG

Aquarium keepers and reef keepers have already answered this question for themselves. PETG shows up again and again in fish tank and reef tank forums as a safe choice for printed parts, once it is printed clean and rinsed.

This is not just one or two opinions. Reef keeping forums, hobbyist video channels, and reef supply sites all repeat the same answer. Nobody is claiming a lab tested every batch of PETG. What they are saying is that PETG does not leach anything they can detect, does not break down in water, and has a long track record in reef tanks and freshwater tanks alike.

We did not invent this reputation. We are printing in the plastic the hobby already picked, for the reasons the hobby already picked it.

PETG vs PLA vs ABS for submerged parts

PETG holds up in water better than PLA or ABS, which is why it is the plastic aquarium keepers reach for. PLA and ABS both run into problems once a part sits underwater for a long time.

PLA is easy to print, but plain PLA breaks down over time in water. It can get soft and turn cloudy or gummy after months submerged. ABS resists water better than PLA, but it can warp with heat and is not a material aquarium keepers commonly trust for tank parts.

PETG sits between the two. It handles water well and does not break down the way PLA does. That is why every submerged part we sell is PETG, not PLA or ABS.

Why we do not use dyed, carbon fiber, or glow filaments

We only print submerged parts in plain black, white, or Frost PETG. We do not use dyed colors, carbon fiber blends, or glow in the dark filament on anything that goes underwater.

Dyes and additives are extra ingredients on top of the base plastic. Nobody has tested every dye and every additive for years of tank contact the way plain PETG has been tested by the hobby itself. Carbon fiber filament also sheds tiny fibers as it prints and wears, which is not something we want anywhere near a fish tank.

Orange and carbon fiber filament do show up in some of our parts that never touch water. Anything that goes in your tank stays black, white, or Frost PETG.

Rinsing a new printed part before it goes in your tank

Rinse every new part in clean water before it goes in your tank. This is a simple step and we ask it on everything we sell, not just one product.

Printing leaves light dust and the smell of warm plastic on a part. A rinse under the tap, or a quick wipe with a soft cloth, clears that off before the part goes near your fish or shrimp.

Some keepers soak a new part in dechlorinated water for a day before adding it to the tank. That is not a step we require, but it is a fair extra precaution if you want it.

What we can and cannot promise about your livestock

We print in PETG, the material aquarium keepers have used submerged for years. We cannot promise your fish or shrimp will be completely safe, because we do not control your tank.

Water chemistry, tank mates, and how you use a part all matter, and those are things only you can see. Rinse the part first, watch your tank after you add anything new, and use your own judgment the way you would with any new item in your tank.

This honesty is not us dodging the question. It is the same answer any responsible fishkeeper would give you about any new item, printed or store bought.

Frequently asked questions