Heater placement questions

[darkpet]

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?

Totally agree. Circulation is key. Also, make sure the heater's wattage matches your tank size. A 20 gallon usually needs around 100 watts.

[furryoak]

I've got a 20 gallon too, and a 100 watt heater works just fine. Just keep an eye on the temp for the first few days to make sure it's consistent.