water change question

[stonepilot]

how do you change your water without uncovering the objects in the tank. in the case that your rock and corals are very close to top of tank, do you take out say 10 gals on a 30 and then add back or do you take from one side as you add to the other hopeing to get out the old water for new. thanks for your help.

[Tanked]

I have a sump I take 15 gallon from the sump then replace it

[jerryc]

You don't need to change more thin 10% unless your having a problem

[Sweetpea]

I have xenia really close to the top of my tank, and only once did I need to do a water change big enough to leave them in the open. While the water was siphoning out, I used a medicine dropper to gently squirt them with water to keep them wet. It woked for the xenia...

But I second Jerry's comment - your normal water changes generally wouldn't need to be more than 10%. How often are you doing your water changes?