time to change water but worried about heater

[fyaplam]

The heater instructions say to unplug it for 15 minutes before doing a water change or removing it from the water to protect it from thermal breakage. Also there is a water level it has to be at, which when I perform the water change the water level will be below where it is supposed to.

My questions are:

How stressful will it be to the fish to do this water change with the heater having to be off for 15 minutes before I can even start (It will take me about 10 minutes probably).

Is it ok to have the heater completely submerged in water, or does it have to stay at the water level. I'm just wondering if the water level is a minimal requirement for how deep the heater has to be in water, but it doesn't matter if it's submerged more than "the water level". My problem is the heater has been installed a little low, and I want to preferably get the tank filled to 1/2" to the top instead of the 1 1/2" it's at now, but I don't want to burn out the heater or shock the fish or prematurely wear it out.

 

[NikkO]

It shouldn't be that stressful to the fish if there is a slight temperature change. If your heater is submersible then yes it is okay. I put mine a little below half of my tank's water level so I don't have to worry about it.

 

[Jason01]

only off for 25 minutes? When my heater failed in the on position(wouldn't shut off, kept on heating), my fish went for about 20 hours without a heater. It took the tank allmost 10 hours to cool off to 68(the temp of my house). In 25 min. you will not really see a temp drop at all. Actually, the temp of your water that you add will probably change it more than the heater being off. If it is a submersible one, you could just pull it off its bracket, and set it on the bottom. Don't do that with a non-submersible one though......

 

[TPIRman]

Is it ok to have the heater completely submerged in water, or does it have to stay at the water level. I'm just wondering if the water level is a minimal requirement for how deep the heater has to be in water, but it doesn't matter if it's submerged more than "the water level". My problem is the heater has been installed a little low, and I want to preferably get the tank filled to 1/2" to the top instead of the 1 1/2" it's at now, but I don't want to burn out the heater or shock the fish or prematurely wear it out.

You can completely submerge it (assuming that it is a submersible, rather than clip-on, heater!) -- that fill line is indeed a minimum line, so feel free to fill higher than that.

As for your water-change question, don't worry about turning the heater off for a while. The fishes will be fine -- especially since you will not be risking the destruction of your heater.

If it is a submersible one, you could just pull it off its bracket, and set it on the bottom.

This actually isn't advisable -- you don't want your heater in direct contact with the gravel.