The BAOSHISHAN 42-gallon Aquarium Chiller seems to be pretty well-suited for a 40-gallon axolotl tank. The manufacturer designed it to handle tanks up to 42 gallons, so your setup is within its range. Based on our research, several people have had success using it to keep the water temperature around 60-65 degrees Fahrenheit, which is ideal for axolotls. You might find setting it up takes a bit of effort, but once it's going, it does a good job keeping things cool for your little buddies.
A big part of what makes this chiller effective is its high-efficiency, Freon-free compressor that works with a 600-800L/H water pump. Circulating the water effectively is key to cooling it down.
Though this chiller comes with a pump, some folks mention that upgrading to a higher quality pump may improve performance and help the chiller last longer.
The chiller also uses a pure titanium evaporator, which helps it exchange heat efficiently, making it a good fit for both saltwater and freshwater tanks. It has two quiet fans that help disperse heat, so it runs pretty quietly—a nice bonus for all that tank equipment.
From what we’ve found, the chiller tends to work best with tanks under 42 gallons, especially when it gets pretty hot. For the best results, try to keep your tank's temperature between 68-79°F (20-26°C), although axolotls generally do better in the cooler end of that spectrum.
All in all, the BAOSHISHAN chiller offers reliable cooling for a 40-gallon axolotl tank. Just be ready to put a little work into setting it up, and maybe think about getting a better pump if you're aiming for top-notch performance. It's definitely a step up from using fans, which can cause more water to evaporate.
