FinnexAquarium Digital Heater Controller, HC-810M

Dependable controller. Have been using it for over three years now. No issues so far.

Been running this controller for a little over 6 months now with two finnex 300w non-thermostat heaters in my sump for a 125G freshwater tank. This unit has worked flawlessly so far. Love the high/low limit alarm. Comes in handy especially when dialing in your temps. The temp probe lead is a bit short however, the length should be as short as possible for accurate measurement. Also, tanks that require controllers usually run a sump system. My heaters are placed in the return pump chamber and the temp probe is in the chamber immediately upflow. That effectively puts the probe at the furthest point away from the heaters while physically only a few inches from the heaters in the downflow chamber. The lead length is perfect for this kind of setup. I monitor tank temp at either end of the tank, one in the temp probe chamber, and one in the sump chamber. I get no more than .5 degree difference between all the thermometers. This is one of the advantages of running sumps. Just ordered my second controller and a heavy duty splitter for dual 150 Aqueon heaters. Highly recommended and is purpose built for aquarium use in comparison to other controllers on the market that activate heaters and cooling systems.

This unit sits outside the fish tank, allowing you to control the heating unit in the tank without getting your hands wet. It remembers your setting, so losing power isn't a big issue. The display is nice and bright and the numbers are big and easy to read across the room.To use it, you plug your desired heating unit (purchased separately) into the control box and drop the sensor from the control box into the tank at a place where it isn't near the heating element (you want the average temp in the tank, not the temp next to the heating element). Set your desired temperature and it will turn the heating element on and off to keep the proper temp.If you have big, nosey or toothy fish, you might need to protect the sensor in the tank, try hiding it with decor or putting a plastic tube over places they can easily reach. My two spot foxface duels with it a lot. My harlequin wrasse used to tug and chew on it and drag it around. Even though it has a sucker to secure it, they love playing with it.You may need to use a separate method to measure the temperature for a day or two as it can read a degree or two different than the water temp. I keep my tank at 79, but if I set 79, it goes to 80. Simple solution is to set it for 78 and it's always right at 79.The control box can control different elements. My box will run a 500 watt or 800 watt element. Bigger elements are needed for bigger tanks. Talk with a fish pro if you aren't sure what wattage to buy. I have an 800w for a 120 gallon salt tank.. It comes on and off a few times each day, for a just a little while at a time.Their heating elements are surrounded by a nice tough plastic so you won't burn the fish, or your plastic items.Would definitely recommend these over eheim in tank heaters for ease of use and accuracy.

I have several of these units and use to brag and encourage others to buy- BUT for the second time (2 different units) have failed in the ON heat and not alarm while over heating my tank. 2 tanks of Discus boiled by this brand controller. First one was sent back and replaced under warranty but when it happened the second time I was done. I lost 22 Discus due to this device failure. Both times it locked the heater ON and failed to alarm above my presets. Lost all trust

In an attempt to maintain an even temperature in my 55 gallon aquarium, I installed two 150 watt heaters, one at each end of the tank. This controller is fantastic for controlling these two heaters. It was as easy to setup as it could be, and has kept the water temperature within one degree of what I set it for. Even after power outages, the controller performed perfectly.