Freesea temperature control is easy to adjust. Performs very well. Inline adjustable heater control. Easy to adjust and easy to read.

Great product for my 3 gallon tank. Used it in a 5 gallon tank, now a 10 gallon. I have it fully submerged on the bottom of the enclosure utilizing the suction cups.

I honestly prefer this to it always keeping the temp higher than what i set it at.

The temp readout is all over the place and not accurate at all. Had to bump up to 80 to get up to between 74 and 75. When the heater indicates 88°f, my thermometer that i trust reads 76°f. The number provides a false sense of security.

This is the maddest/saddest i've ever been over a product. Lost 3 24k guppies and 2 l333 plecos, as well as their eggs. The one with this heater is super cold and my poor betta is suffering. It never suctions properly to the tank wall and has a huge g...  Read More

The fluval e-series is the best aquarium thermometer on the market. I have a 30 year old 44 gallon fresh tropical water pentagon shaped aquarium. In my 29 gallon high, the 200 watt works great.

Led back-lit lcd display is nice and makes checking the temp very handy. Microprocessor control makes setting the temp easy, as well. Lighted digital display in tank is a bit unsightly, but it is easy to read.

Took me a while to finally purchase this due to all the bad reviews. I'm sure many have had defective units but these heaters are wonderful when functioning properly. I've never had that issue, so i think it's more about aesthetics than anything else....  Read More

It never fluctuates. Turning it down to 75 is fine, but since it will reset to 77 automatically after being powered off (or a power outage), that's somewhat annoying.

No problems with lf (low flow) warnings on the display or wild heating or cooling. I have to buy and place a wavemaker close to the heater and problem solved.

I suspect this was simply a faulty unit as i have a fluval 306 filter. Temp reading is always off.