[Shangrila]

So my sons(twins 14 yrs old) have 1 20l and 1 10 gal in each of their bedrooms for the last couple of years. Recently they got bit by the betta bug and have a 1.5 gal 3 compartment betta tank in each room also. They are concerned that when it comes time to put on the A/C the bettas are going to be cold. How does one go about heating a small tank? In the summer time the rooms could get as high as 85f and with A/C on go down to 63f.

P.S. No bashing about the small tank for the bettas, these kids change water 2-3x weekly and never over feed. Eventually they will probably switch to 1 gallon decorative bowls for each one, but that could be a few months away and still leaves the dilemma of heating multiple small tanks.

 

[Briz]

The Hydor Theo is one of the smallest submersible/adjustable heaters that many of us use.

They aren't as good as Eheims but for the size/price they usually get the job done.

I have to be careful with mine sometimes when it gets really hot in the house that the heater does in fact turn off.

 

[acitydweller]

Hi Andrew,
Glad to see the boys following in their dad's footsteps. The Hydor theo 25wruns on my 2.5g betta tank and has been for 3 years so far. 50w theos run on two other 10g aquariums for around 2.5 years.

links arent allowed but search on amazon for "Hydor 25W Submersible Aquarium Heater ". its currently selling for $16.65 shipped free with prime.

The 25w eheim jager is a longer heater.
the 25w cobalt heater is the most accurate bar none but costs $8 more.

Skip the marina mini and tetra as they are fixed and non-adjustable. ive had two of each and all four failed by failing to shut off, killing my livestock. i would have chalked that up as a fluke if not for them failing twice.

 

[AquaAurora]

I love the ehiem jagar heaters, changed all my tanks heaters over to it, even have a 25 watt to heat water for w/c that is drawn from just cold tap. Unfortunately its bulky and not so easily hidden. I won't touch pre-set heaters especially the small ones for "betta tanks" and such, read to many horror story reviews of them failing and baking fish/shrimp or even pealing their paint/coating and the chemicals released from this poisoning fish.

Its definitely good to heat betta tanks, they are tropical fish and though they can survive small quarters, and cooler waters, they won't be as happy or active. I wish you luck in the search for a reliable heater that doesn't take up most of the tank!

 

[lauraleellbp]

Not bashing, but a major part of the issue here in regards to heating is that 2.5 gallons of water is the smallest volume of water that can be held at a stable temperature by the heaters we have available at the hobby level.

It's for this reason that I personally always recommend bettas be given at least 2.5gal.

+1 for ALWAYS get adjustable rather than pre-set heaters. Pre-set heaters especially seem to fail during seasonal weather fluctuations- they either don't switch on soon enough, or don't switch off when they should, creating really drastic temperature fluctuations. I find that I have to adjust almost all of the thermostats on my heaters from summer to fall and from winter to spring to keep my tanks at the right temps as the ambient temps in the house start changing.

 

[cjstl]

Cobalt makes a tiny thermostatic heater, but it is expensive.

I have a couple of Marina Mini heaters. They haven't cooked any of my fish yet, and were only $10 each. But it drives me crazy that there's no temp indicator on the heater. You just turn the knobs until you get it right and then leave them.

 

[KnownSyntax]

I would honestly ALWAYS go with a adjustable heater, as most (if not all) "betta" heaters are always pre-set and have horrible temperature swings. I had one before my little Betta passed away from bad health (tried to save her from dying in the little cup but was too late in the end) and the first day I would see the temperature go from ~75-84 at one point, and it still was on and heating.

Like the others have said you'll need at least 2.5 gallons to have a good set temperature as using anything smaller will lead the heater to heat too much at a time.