Keeping fish at lower temperatures

[GreenCircleGirl]

I am quite fascinated by Cory’s video on keeping fish without a heater. I’ve lowered my heater temperature to 75 degrees.  Can I go lower safely?  I have a n Amazon puffer tank with Cory cats and a Bristle nose pleco.  I also have a mixed tetra tank with zebra loaches and electric blue acaras.  A tank of multifasciotus    A mixed tetra tank with Bolivian rams. I have an Oscar tank and a tank of geophagus tapejos and a chocolate cichlid. 

[Guppysnail]

I have kept albino Cory an BN pleco at low of 72 no ill affects. I currently keep lemon BN pleco Pygmy and panda Cory at 74 lights push it to 75 day time. My pandas lay eggs almost weekly my pleco lay monthly like clockwork all 3 types very active. Not as low as I am sure you are asking but it is a 1 degree difference 

[xXInkedPhoenixX]

I run low tech tanks with no heaters. Caveat for me is I keep my house a little warmer because I prefer it that way myself. My thermostat is generally at 72 this time of year and the rooms my aquariums are kept have a space heater set between 76-78 depending on my mood. With that in mind the rooms my tanks are in that sit side by side do have different climes one is often significantly cooler than the other. My coldest tank sits next to an indoor thermometer that read 73 this morning and my other tanks sit in a room (same brand thermometer) that was 75 this morning. 

My 5 tanks last tested at 75.6, 75.9, 77.7, 76.3, 76.1....recently I'd turned off the heater in the house (it's the time of year it can't decide if it's winter or spring) and I'd forgotten to turn it back on at night. The house was a lot cooler in the morning (though the space heater in the rooms was still on it was the only source of heat). The tanks went down in temp of course the lowest to 73.8. This is a tank that I have Otocinclus Vittatus and at the time housed my Harlequin Rasboras. Nobody in this or any of the tanks were negatively effected. Part of this I think is due in part to them being used to natural fluctuations in temperature as every living creature generally does throughout the day. If they had been used to heaters and say I forgot to plug one back in or one broke it may have been an issue. This is why I never use them- it's one less thing for me to worry about and my fish do well. 

Of course there are exceptions, Discus, Bettas off the top of my head I would absolutely use a heater for- so choosing the right inhabitants also play a part. I knew what kind of tanks I wanted to run so I chose inhabitants that could tolerate a wide range of temperatures. 

I thank Cory for his video about no heaters....even after having seen that and done my research I got a bit peeved when I lost all but one of my first batch of Otos and the fish store employee told me the reason they died was because my tank was too cold. It's the same temperatures today and the batch I got from a different store still lives there and has bred. It made me feel bad at the time though I also knew better. Shaming your customers into buying something they ultimately don't need is bad practice. Like I said though, always exceptions- but I wouldn't have tanks any other way. 

Edited March 19, 2022 by xXInkedPhoenixX