Yes, especially if they should have one anyways. Change the settings very gradually so they don't get shocked. Test it in a separate container first, to be safe.
Add an aquarium heater. Make sure you choose a heater with the correct wattage for your aquarium's water volume.
what type of aquarium tropical (heater needed) cold water or marine (saltwater)
Lighting, both direct (lightstrip) and indirect (sun in the window), all motors including pumps/filters, room temperature
A 50 watt heater is major over kill for a 3 gallon tank, a 10 watt heater is more than enough for a tank that size. You will nuke your aquarium very quickly the first time the 50 watt heater sticks on, with a 10 watt heater if it sticks on the aquarium temp will only raise a degree or two.
No it is no safe to, it will probably kill you battery. It uses 200watts.
Usually when you purchase a water heater for the aquarium, It keeps the temp between 72-78 degrees. I have a ten gallon tank with a heater in it and have never had a problem.
On most any heater, yes. The temperature you'd commonly be looking for is about 76*-80*F. This will vary though depending on what you're wanting to keep.
Not sure what you are asking here, broke as in not working? or broke as in pieces of glass are in the tank? If the heater is not working, you need to purchase a new heater. If the glass tube is cracked or broken and pieces of glass are in your tank, then you need to unplug the heater and remove the glass from the tank.
There are many necessities when setting up an aquarium. One will need a tank and proper lighting. A skimmer to skim the water, rocks, a heater, and regular maintenance tools are required as well.
adjust the heater on your tank, it will take a while to change the water temp, so as long as it is gradual, it wont hurt em
Medicines for fish are readily available both locally in pet stores, and from online stores to treat a variety of illnesses. The only additional items that you should have on hand are an aquarium heater and aquarium salt.
No. Guppies need a heater, whereas gold fish will overheat. Also, they will eat the guppies.