How long you got? This could take a while ...
Ok, here's one. I've been trying to set up a frag tank for a king's age (probably something like 12 to 16 weeks). Everytime I just about get it online, something happens, and I have to abort, rethink things, try again after a few days.
All I had to do tonight was hook up one little hose to one little hose barb that's threaded into a bulkhead on the main sump.
The catch: there's a small piece of tubing on the hose barb already from the time I had to cut the tube after the last aborted attempt.
Wiggle, wiggle, wiggle. Grumble, I hate trying to pry hose off these stupid little barbs. Wiggle, wiggle, SNAP. Oh crud, that didn't sound good.
Yup, a little 6" crack above the bulkhead on the sump.
Grumble, swear, grumble. Off to the garage to find a piece of scrap glass to silicone over the crack.
Find a piece, clean it off, scrape scrape scrape the old silicone off, polish some more, etc.
Ok. ready to smear the silicone on.
Grunt, man this silicone is tough. Ok, old tube, throw it out, get another.
Smear smear smear. Now over to sump to press it on.
Hmmm, can't squish the air bubbles out. Ding

Idea. Go get the clamps.
Clamp the glass. Grunt. Stupid stiff clamps, they're all rusty (just like the rest of my tools. How did they got all rusty anyhow. Just because my tool room is also my tank room ....

). Ok, clamp clamp clamp.
SNAP.
Now the crack goes all the way to the top of the sump.
Dog gone it, I says. Oh well, the patch will hold.
Um .... I guess the dripping coming out from the patched glass tells me otherwise.
Hmmmm now what? Take one of my 10g's and use it to replace the 50g of sump?
Ok. New idea. Drain the sump, find another piece of glass. Clean it off, patch the inside of the sump.
Hey, is this silicone safe to use? Wife asks. Of course it is. See, it says "100% silicone." Everyone knows that's the stuff to use. "Not for use on aquariums" wife points to the instructions. Um. They put that there so nobody can sue them. Yup, yup, uh-huh, uh-huh. Not to worry. (ok, so now I'm worried.. But must put on brave face.)
But, two patches of glass and a full tube of silicone. Surely this will work out (well I guess I'll find out when it comes time to refill the sump in a few days.

)
Moral of the story:
- don't start something at 10pm on a Sunday. The stores are closed if you have to run out and buy a whole new tank in a hurry. IT DOESN'T MATTER if it's "connect this hose to this hose barb." What could possibly go wrong? Apparently ... A LOT. A @%$^%$!!!! lot can go wrong.
- Silicone is nice to have onhand.
- So are scrap pieces of glass.
- Smile! Because Santa may be watching, and may not like to hear creative ways of expressing frustration.
Sigh. So still no frag tank for me. And a drained sump until the silicone dries.
Wife asks, "have you heard of other people successfully fixing cracks like this?" "Oh sure. All the time. Not to worry."