Stupid Question re Water Changes

[Fast Eddie H]

Please forgive my ignorance, but I am a newbie to SW and am getting ready to do my first water change. I have a 90 gallon AGA, with a 40 gallon sump and 25 gallon fuge. My question is this.
I have never had a system with a sump before. When doing a water change, do you first unplug the return pump and let the water drain back into the sump or do you keep everything running? I ask because it seems that if you leave everything running and remove water, your main pump would eventually run dry as there would be no more water draining out of the tank due to the drop in water level.

Again, I am sorry for the stupid question, but I want to make sure I am doing things right.

 

[tagraham]

change the water out of your sump not your display. the level in the display wont change.
maby that is what you are doing and im the stupid one idk

 

[Pistonkev]

Bingo shut your pump off and take it from your sump.

 

[scrmbld33]

i shut off the return on mine for water changes, siphon out crap then add the new water to the tank

 

[clevername]

I take water directly out of the tank and let the return run dry, then turn off the sump (to keep from over heating). Then i add the new water to my sump thats turned on.

Only reason i do this is because i take out more water thats in my sump, so just turning off the sump and taking water out wont work because theres not enough drainage.

 

[PatMayo]

I turn off my sump pump and take the water from the sump. I change 12 gallons per week and my 30 gallon sump works perfect. After I fill the sump back up I just turn on the pump and away I go. Very easy. I have two 300 watt heaters in the sump. I always make sure I turn off my heater controller before I change the water. Just in case.

Regards,

Pat