In this thread post your most idiotic reefing mistake

[FishyFishy!]

I've been lucky enough to not have anything crazy. BUT

I have overflowed numerous buckets by not having an auto shut off with float valve on RO units. Also spilt many many gallons of water not securing syphon hoses to the tank properly.

The worst was building my 187. First, I spilt an entire large can of PVC glue onto my new carpet. That sucked. Goodbye carpet. Then when I turned on the dart return pump for the first time, I had two (not one.. two haha) of the loc-line return lines pointed up over the rim of the tank. Not only did I get a mouth full of water as soon as I stood up, but there was a tonne of water on the floor, AND in a race to point them back down I knocked the 72" 12 bulb constellation fixture into the water. Luckily I had a GFCI plug in, it snapped before anything was harmed. I let the light dry out for a few days and it worked great after!

[peterss1975]

Went on vacation in Mexico and while there I checked my controller and noticed my sump was really low. so I decided to turn on my Top off pump. All was good, filled up enough where I was happy. Went to turn it off and lost my internet connection. I scrambled to turn get reconnected so I could shut it off. I finally was able to reconnect to shut it off but had no idea how much flooding happened until I got back home. Luckily I got and no flooding at however I couldn't fit another drop of water in sump.

[Magickiwi]

My biggest mistake wasn't really my mistake exactly. I simply listened to the dude at the LFS when he said a green brittle star was reef safe. Well by reef safe he meant it wouldn't eat corals, what I THOUGHT he meant was that it would co-exist without harming anything in my tank (Normally what is meant). Several fish later I finally caught the bastard in the act and then had to take apart large portions of my rock work to get the big sucker out.

Lesson learned: People at the LFS aren't necessarily speaking in the same context as you so do your own research and trust nothing unless you've verified it with a valued source.

[xenon]

About 6 years ago, I attempted to QT my fish with ich in hyposalinity (1.009).

I dropped them from 1.026 to 1.009 properly (3 points per hour).

I noticed the fish not doing very well once I got to 1.009 so I quickly added some salt to the water and they bounced back. The following day I got some proper calibration fluid and I was off my 3 points. What I thought was 1.009 was actually 1.006.

Lesson learned.

[Madreefer]

Originally Posted by Magickiwi

My biggest mistake wasn't really my mistake exactly. I simply listened to the dude at the LFS when he said a green brittle star was reef safe. Well by reef safe he meant it wouldn't eat corals, what I THOUGHT he meant was that it would co-exist without harming anything in my tank (Normally what is meant). Several fish later I finally caught the bastard in the act and then had to take apart large portions of my rock work to get the big sucker out.

Lesson learned: People at the LFS aren't necessarily speaking in the same context as you so do your own research and trust nothing unless you've verified it with a valued source.

I think this is the biggest mistake we all make especially when starting out. It took me a couple of years to wise up and stop listening to guys at LFS

[Parker]

Don't set a 400w fixture on your center brace.

[trilinearmipmap]

OK mine looks like the 3rd worst mistake after the cracked centre brace and the light fixture dumped in the tank. Now I don't feel quite so stupid.

[monocus]

putting a helfrichi gobie in my tank.my male bird wrasse had a $140 lunch in less than 10 seconds