tboned, you are my personal hero for today, and probably for a long time in regards to this tank.
Ther is no way we could convince my parents to let me drill the tank, and given that we only paid $25 for our 150, if it cracked, we'd likely just sell whatever was left.
We had tried many other PVC overflow solutions, to no avail. They either lost the siphon while running or didnt keep the prime, and would have caused disaster during a power outtage.
Then I found yours. We modified it a tad, using 1.5 and 2 inch PVC to hopefully handle a little more flow. We also added teeth to the intakes, and let me tell you, this is an amazing work of engineering.
The valve on top isnt necessary, but it was used on an older attempt at an overflow, and I think it looks neat. Sort of like a mad scientist project type thing.
So thank you for the detailed instructions and amazing work. It restarts perfectly during a simlated (and hopefully the real deal) power outtage, and I think it will be even better once we get the aqualifter pumps instead of the powerhead.