Rebuilding hardware set up

[jassz]

Hi all.

I would like to rearrange my set up, for several reasons.

• I would like to move the wiring to a safer place (currently hanging precariously next to the sump)
• I would like to make the plumbing a little neater
• I have a protein skimmer to install (currently sitting on my floor)
• I have a second in line heater to install

Ideally, to accomodate all these changes, I would like to simply disconnect everything, make the changes, and then reconnect. But I'm scared to disconnect things in case it floods! Logically, I think they would not design a system that would flood should the power happen to go out. On the other hand, there are 135 gallons in the upper tank and only 40 in the lower, and it sure looks like gravity would take it all down to the lower tank! I've never had a sump before (or a sw set up), so any reassurances you have would be most appreciated. I turned everything off for a few seconds, but when the sump started to fill I panicked and turned it back on again.

Suggestions?