New (7) from $11.25 Sold by ZANY Values and Fulfilled by Amazon. Hydor Slim Heater for Bettas, Bowls and AquariumsDetailsZoo Med Laboratories AZMBL20 Betta Hammock Add-on ItemFREE Shipping on orders over . 7.5 Watt, Round, up to 5 gal Betta slim heater helps guarantee your fish a healthy life by promoting the ideal water temperature. Specially designed with the innovative positive thermal coefficient element to heat the temperature of your bowl, aquarium or terrarium an average of 5 to 10-degree warmer than room temperature. 3 x 0.2 x 3 inches Shipping Weight: 1.6 ounces (View shipping rates and policies) Item model number: T20101 #22,461 in Pet Supplies (See Top 100 in Pet Supplies) in Pet Supplies > Fish & Aquatic Pets > Aquarium Heaters Bettatherm Mini Size Betta Bowl Heater Cobalt Aquatics Mini-Therm Heater, 5 watt Deep Blue Professional ADB12881 Bettastik Sub Heater for Aquarium, Mini, 7.5-watt 5 star49%4 star17%3 star9%2 star8%1 star17%See all verified purchase reviewsTop Customer ReviewsElectrocution Hazard|

Works as advertised and is inexpensive|Pros:1) Inexpensive and stupid simple to install2) Works well in 3 gallon volume of waterCONS:1) "Always On": it does not have on/off when it hits a certain temperature thus it will keep raising temperature in a small volume of water. fish tank lights edmonton***BECAUSE OF THIS YOU NEED TO MONITOR YOUR TEMPS CLOSELY, ESPECIALLY IN WARM ROOM and/or SUMMER!!!fish tank light bulbs for plants***2) DO NOT recommend this heater for anything smaller than 3 gallons, see notes.3) Even with gravel on top and lots of power cord slack, this heater has a tendency to want to "float" up to about the gravel line no matter how deep I put it under the gravel (have about 3/4 inch gravel on top).fish tank water filter setup

BOTTOM LINE: Solid BUY if for 3-5gallons of water. If you are looking for a Betta tank heater for this volume of water, this is the one to get.NOTES:Bought this to initially heat a 1.5gallon tetra aquarium (see review) Tetra 29137 WaterWonders Aquarium Cube, 1.5 Gallons, Blackand it would raise the temp too high for Betta(upto 87F in a room that is about 75F). fish tank water chlorineMoved the fish and this heater to 3gallon tetra tank Tetra Cube Aquarium Kit, 3-Gallon and temps ranged from 77-81F throughout the day. fish tanks for sale asdaNot sure if that's too "wild" of a temperature sway in 24 hours but my Betta does not seem worse for wear or stressed. small fish tank malaysiaWill update this review if something changes.

Perfect Heater for Betta|No wonder why it's the BEST SELLER!|Heater stopped heating and melted!!| See and discover other items: betta fish accessories, big water bowl, 1 gallon fish tank heater, small castles, betta fish bowlA reader wrote in, "I have been advised that my betas are dying because the water is, perhaps, too cold. My home is heated to around 65 degrees. The heaters at the store are too large for my desktop bowl. I once had a stand with a light bulb underneath – very cost effective – it wore out and I cannot find anything like it – do you know of a source?"Many Betta owners are not aware that their Betta requires warm water. Not just room temperature, which ranges from 68-72° F (21-23°C). Ideally, the water should be at least 78 degrees for a Betta. Because Bettas are often kept in small tanks or bowls, heating can be a challenge. Changes in room temperature, especially in climates that become much colder at night, can prove stressful for a Betta.However, there are now a number of small heaters made specifically for mini aquariums and Betta bowls.

Before choosing one, it’s important to know a few things about heaters, so you know what you are getting.The term submersible refers to a heater that can be fully submerged in the water. However, some vendors use the term “partially submersible”, which means that a portion of the heater must remain above the water line. Generally, partially submersible heaters cost a bit less, but in use they are not as versatile. I recommend going with fully submersible heaters whenever possible, no matter what the tank size. Pre-set heaters come with a single preset temperature, generally 78 degrees F. There is no way to adjust preset heaters; they simply turn on and off as needed to reach the factory settings. However, they are often smaller and less expensive, which makes them a good candidate for small tanks or bowls. Adjustable heaters come in two varieties. One has temperature markings that allow a specific number to be selected. The second type has an adjustment know with only a plus and minus on it.

These heaters have a small light that comes on when the heater is putting out heat. To adjust the temperature setting; you must place a thermometer in the tank, turn the heater on and wait for the temperature to reach the desired level on the thermometer, then turn the knob until the light goes out.I generally recommend an adjustable heater with actual temperature markings on it to allow for precise adjustments. However, for a mini tank or bowl, I favor the pre-set variety, primarily due to the smaller size and ease of use.Here’s where things get interesting. With the advent of very small heaters, manufacturers have moved beyond the standard torpedo style heater that is suction cupped to the side of the tank. Heaters now come in a variety of shapes and sizes. Some are flat, others are rectangular shaped, and others are round to fit in the bottom of a bowl. One thing the all have in common is that they are made from shatterproof materials and require little energy to run. Flat styles can be placed under the gravel, this avoiding the need to try to hide the heater behind decorations.

It is even possible to place them underneath the tank itself.Periodically the question is raised about the possibility of an in-line or in filter heater. These are available, but they designed for larger tanks. Currently, there are no models made for small aquariums. Hopefully, in the future someone will come up with a heater/filter combo designed for small aquariums.Regardless of the type, size or shape of the heater, you have no way of knowing what the temperature actually is. Therefore it's important to use a thermometer and check it regularly to ensure the heater is not under or over heating the water. Small stick-on thermometers are ideal for mini aquariums and are quite inexpensive.If the tank is very small and a stick on thermometer would be visually unappealing, a "standing" thermometer can be placed in the tank for a short time to take the temp, then removed. Which should you get for a small Betta tank or bowl? I’ve had great success with the flat styles that can be placed under the gravel.