ViaAqua50-Watt Quartz Glass Submersible Heater with Built-In Thermostat

This is a great fish tank heater. I first used it in my 3.5 betta tank because my first heater wasn't good at keeping a consistent temperature. With the first heater (at first I had no idea that bettas needed heated water so I picked up a cheap disk heater at Petco) I noticed my betta was lethargic, her color was dull, and she had horizontal stress marks on her side. I did some research and decided to get a heater that I had better control over. I'm so glad that I got this one. Now she is zooming around and her color has gone from a soft dull blue to a very vibrant almost purple color.It keeps my tank between 72-80 degrees, doesn't over heat it and I can decide how warm the water is. My old heater would only heat the tank to about 6 degrees F above room temp which isn't always great for a betta. It was also hard to tell if it was actually working. It never got the 3.5 gallon over 65 degrees which wasn't even more than room temp and not warm enough for a betta. If you have a small tank and are thinking about one of those heaters, don't do it. Although this is a bit more money it is worth it.It's easy to tell when the heater is working because you can see the orange light come on. It's also easy to see what temperature you have selected on the front of the heater. It works by using a dial and when you turn it, a red line goes up to the selected temperature. I have since upgraded to a 10 gallon tank and this heater works well for it too. I keep the heater at a lower temperature because the tank light also heats up the water.

I've had this heater for several months now, and I'm pleased to say that after I installed it and tweaked it over a few days to get the temperature where I wanted it, it has been completely hassle free. I own a 5 gallon bow front acrylic tank, which houses one betta fish. Easy to set up, but you do have to play with the dial a little to get it where you want it. You DO need an actual thermometer to double check the heater- be sure to put it on the other side of the tank. You can buy a good one at pet stores for $2-$3 though- you'd need one to check the water when doing water changes anyhow. I set it where I'd guess 78º and the water was hanging out around 82º, so I dialed it back until I got a consistent 80º for my little guy. Once I got it where I want it it has kept the tank at that temperature consistently. Just be sure to wipe down the heater and the suction cups every now and then when you do your water change, as things like to grow on the suction cups where it's nice and warm. Winter is coming up here, and I think my betta will be the warmest coziest one in the house. :) I'm glad I followed the advice of many other fish owners and paid extra for the good reliable heater, and I'd advise you to do the same!

Running strong since 2019 and its now 2025 in my 10 gallon. it has discolorations but has always been reliable. im looking to replace now and not sure if i will rebuy or not.

I wanted to hold off on reviewing this until I'd had it for a while. I have several heaters in this product class, and sometimes they disappoint over time. After six months, this one is my favorite by far.The thermostat has been consistent for me - which is the most important concern with cheap heaters. The 5 gallon I'm using this on has kept a consistent and appropriate temperature.The temperature adjustment is easy to turn, and the setting is large and easy to read. In fact, this has the best display of any thermometer I have seen in the under-$50 range. All my other heaters have scales that are indecipherable once actually in the tank.I previously have bought 50w Hydors (a commonly recommended 'brand-name') and have nothing but frustration with them. Inconsistent temperatures, difficult adjustments, and premature failures.There are a couple downsides. The temperature scale is totally out of sync with the thermostat. This seems typical for this class of heater - always set it by your tank thermometer, don't rely on the scale! Secondly, it's a bit large - it takes up more physical space than some other brand-name heaters. But these are minor nits.I'll likely be returning to buy more of these in the future.