Live and learn my friend! It happens to everyone, my brand new Current IC lights crapped out on me the day after I added some plating and hard corals fro the first time. I was lucky to have an old T5 sitting around and threw it on so nothing died.
There's a thread on here about the "dumbest" and generally bad things people have done by accident. Check it out, I'll link it if I can find it, you'll see that even those who have been doing this for years make simple mistakes.
Now, the bulkhead. Just try to give it a quarter turn with a wrench. I had a dripping bulkhead that started three days after filling a 220, an this did the trick.
How is the tank drilled? And what overflow style? Because you should be able to turn off the return, and just empty the overflow and have access to it.
