I went years without drilling my tank. I used several diy overflows (you know us diy'ers, we are always trying something new). I also had a cpr overflow w/aqualifter. My experience was that, even though my syphons were dependable as long as the maintainance was performed, I was relying on a syphon, a pump, and my own due diligence in maintaining all the components. I had slow flows, overflows, etc. I finally bit the bullet and drilled my tank earlier this year. BEST THING I EVER DID!!! So easy. Before drilling I emailed AGA to verify the back glass was NOT tempered. I moved livestock, corals, and most of the live rock to several buckets with tank water. I only drained about 3/4 of the tank, but my tank is only a 45 tall.
The whole project probably took me 3 hours from start to finish, with the hole drilling and bulkhead installation taking all of 20 minutes.
