Who Gives A Fish Forums

I just got a new heater for my 20 gallon tank, but I'm not sure where to put it. Does it matter if it's near the filter or not? Also, should it be horizontal or vertical? I don't wanna mess up the flow or anything.

Placement can affect heat distribution. Ideally, position it near the filter outflow to help circulate warm water evenly. Horizontal or vertical doesn't matter as much as ensuring it's fully submerged and not touching the substrate. What kind of heater did you get?

I've always put mine near the filter, kinda diagonal so it's not straight up or down. Works fine, but I've heard some folks say horizontal is better for larger tanks. Not sure if that's true though.

Lovely wrote: ↑Mon Jun 09, 2025 9:53 pm I just got a new heater for my 20 gallon tank, but I'm not sure where to put it. Does it matter if it's near the filter or not? Also, should it be horizontal or vertical? I don't wanna mess up the flow or anything.

Yep, near the filter is a solid choice. Just make sure it's not too close to any plants or decor that could block the heat. What's your tank temp right now?

Heater placement is key, especially in smaller tanks. If it's too close to the substrate, it can overheat the bottom layer. I'd go vertical near the filter outflow, but avoid direct contact with the glass. What brand heater are you using?

I've had mine horizontal for years with no issues. Just keep it away from the substrate and any decor. Also, make sure it's not near the thermometer, or you'll get false readings.

Horizontal placement near the filter works best for me. It's out of the way and distributes heat evenly. Just avoid putting it near any air stones, as the bubbles can mess with the thermostat.

Thanks for the advice, everyone. I'll try placing it near the filter outflow and see how it goes. It's an Aqueon Pro heater, by the way.

Lovely wrote: ↑Tue Jun 10, 2025 1:12 am Thanks for the advice, everyone. I'll try placing it near the filter outflow and see how it goes. It's an Aqueon Pro heater, by the way.

Good choice. Aqueon Pro heaters are reliable. Just double-check the temp after a few hours to make sure it's stable.

Yeah, Aqueon's a solid brand. Let us know how it works out. If the temp's all over the place, you might need to adjust the placement a bit.