
Here’s what I do ….
Here are my external controller recommendations….
Option 1:

Option 2:
Purchase a robust external heater/cooler controller with 2 plug receivers (for the use of 2 heaters or heater and chiller). I do not recommend the cheaper aquarium controllers made in china ones that you can find on amazon. The brands that I do recommend are Ranco ETC and Johnson A421. The edge on reliability going to Johnson. But make sure it is pre-wired with the plugs and probe. I would recommend coating the Johnson sensor probe (it is some kind of metal or aluminum) by dipping it a few times in plastic dip purchased at Lowes/Home Depot or online for a few bucks. The Ranco probe is a water safe material.
About the Author

Sol Bick
Aqua Creations Founder
Aqua Creations founder and self-proclaimed fish addict, Sol Bick is passionate about anything aquatic. With over 50 years of experience as an aquarium hobbyist and professional, Sol never stops plunging into the depths of aquatic science, researching, contributing to, and staying current with the latest technologies.