Terracotta in the Aquarium

Q: C wrote,

Is it ok to add a small terracotta pot to my betta’s aquarium?

A: While it’s always safest to add only decorations to our tanks that are manufactured specifically for aquarium use, often we are inspired to add everyday items to our aquariums. Terracotta pots are commonly added to aquariums, sometimes broken into bits and other times whole or containing aquarium plants. The color can create a beautiful contrast to the shades of green provided by live or synthetic plants and fish love to utilize them as hiding spaces. Terracotta, however, is not always safe. First and foremost, it’s always best to use a new pot that has never been exposed to fertilizers or soils that contain fertilizers like Miracle-Gro. Occasionally, terracotta can alter your water parameters, specifically pH. Once you have found the pot you’d like to use, place it in a bucket of aged tap water and test the pH. After at least 24 hours test the pH again and observe any changes. If no change in pH is detected the terracotta is probably safe for your fish.

Please note that I recommended the water be

aged prior to adding the terracotta. This is because tap water will often experience sudden drastic shifts in pH once it has been exposed to the atmosphere. Aging the water 24 hours will allow the pH to stabilize and you will get a truer reading. Otherwise, there is no way to determine if the change in pH was caused by the terracotta or as a result of exposure to the atmosphere.

Other types of ceramic pots may be safe to use in your aquarium as well but determining which can be very difficult if not impossible. Personally, I am not familiar with the various glazing compounds used on ceramic pots so if they aren’t your basic terracotta or designed specifically for aquarium use, I avoid them altogether.

Have fun aquascaping and if you have any creative uses for terracotta you’d like to show off, feel free to email me your photo and I will add it to this Blog entry.