Well i went with the extentions :)
Im happy with em but im getting micro bubbles and i assume its them causing it so Ill have to glue them together... but i did a test and only lost 10 gallons and the ATO should cover that so i "should" be home free in a power outage :)
http://img.photobucket.com/albums/v6...h1ca/009-7.jpg

I dont understand this ? You dont want your sensors of the tunze in the display, keep them in the sump.

If your really concerned about drain back. I have always thrown in a check valve more so on the fact my skimmer is very sensitive to water levels and if the pump fails i don't want skimmate everywhere. The Wye valves are really good ones.

http://www.bulkreefsupply.com/store/...s/check-valves

oh no, Sensors in the sump... but the water level would go down there in the event... so when the power kicks back on the ato would fill the missing water till i got home and had to add salt...
My sump drains to the sewer so any extra water is just gone lol

Im looking into checks... I need to add 2 to my system, My skimmer is seperate to my return so he will be just fine with a water drop.
You need to be an engineer to do this hobby lol....its going on my resume lol

I wonder if they would be ok submerged? then i could put them into my overflows and not have to see them or add them too far down my lines?

I dont see why not they are sealed units and act on head pressure to shut them. What size of plumbing did you use i have a few sitting around.

That seems dangerous. I don't know if you realize the tunze will only pump for max 5-10 mins then cut off and go into a safety mode as a backup. 10 mins of pumping with the pump is not all that much water. I would re consider your plans here.

My returns are 1 1/2"

Wait so you're saying that all the water that flows down from the display during an outage is going direct to the city sewers? You have no room to handle the 10 gallons?