[Delphinus]

Oh so many things. (See my signature !!) Where do I even begin.

I think one of them has to be checking to see if the "thing that was causing an electrical problem" was what I turned off, by sticking my hand in the water. <zap> "Um nope it was something else that's still on! Ow ow ow ow ow ow ow somebody please pull me away from the tank ow ow ow ow ow ow". Now that I think of it it's a little like checking for a gas leak with a match. Yes it can tell you whether there is a problem, yes there are better ways to check.

Other things .. It's always the shortcuts and the temporary things that get you. Or the things you do just before bed.

I don't run a beckett skimmer without a collection cup anymore (because once it's full it stops letting the skimmer produce foam). And if no collection cup I run the skimmer in the sump, so if it overflows it overflows into the tank. Things you learn the hard way!

One horrible mistake I made as a rookie, I put a float valve for topup on my reef, it was just hooked up to my household cold water supply. Never ever hook a topup on a SW up to an infinite water supply! What a mess that was. Of course it failed at night. On a related note, it's amazing what can survive being in cold FW for hours on end (that you think couldn't survive such a thing) and it might surprise you what can't.

One that I still feel really bad about, I moved a cleaner shrimp from one tank to another. I had done this so many times I got complacent about acclimitizing. Well it turns out if your salinity deviates by 0.002 (eg., 1.023 versus 1.025), this will kill a shrimp instantly. And I do mean instantly, you may as well drop them in boiling water. Always drip acclimate even if you think your source and destination waters are "close enough" - they aren't!

I could go on but I'll stop to save what's left of my dignity!