which one is better? btn these fish tank heaters?

Question

I want to get a heater for my 30 gal long fish tank. I am planning to keep tropical fish and live plants. I just want to know which heater should I invest in? By the way I have already order the hood that will have two lights 60 watts.
The heater I am want to know is btn the regular hanging one and the submersible one....I guess I will have to get one for 150 watts but I am not sure which one is better?

Answer 1

If you're just deciding between the submersible or not, I would go with the submersible one. You can put it low enough in your tank that you don't have to worry about it being exposed above water and shattering during a water change if you forget to unplug it, and it's sealed, so you shouldn't have to worry about water seeping in if it gets dropped in the tank by accident.

Another thing you might want to consider for a long tank is to get two 75 watt heaters instead, and set them to the same temperature (if it's adjustable). This will give you more even heating throughout the tank, you'll have a temporary backup if one should fail, and if it does fail in the "on" position, the lower wattage is less likely to overheat the tank to a point the fish will die (a thermometer is a good idea to check your temperature regularly!).

Answer 2

In my opinion, a fully submersible one is better as you don't have to worry about unpluging it to do water changes as long as the water level never goes below the heater. If you have a heater that hangs on the back, you have to always unplug it when taking water out, and always plug it back in when you are done. Submersible heaters can be placed so even if you remove 50% of your water, you can leave it running.