So I went down to my tank the other day, heard a strange noise before I even got there. My first squishy step into the fish room made it clear there was a problem.
So I've got a small 15G or so sump; pump is on the left and what would be the wet/dry part is on the right. I had a fairly fine filter on the right -- I was trying to clear out some suspended matter that had been bugging me recently and it was working pretty well. Unfortunately, I hadn't noticed that the filter was getting pretty full. Well... the right column started backing up water. The left column (which is where the return sump is) of course was then lacking water. I have a 10G/hr RO
filtration system that was happily providing make up water to keep the level right. This of course was sending fresh water into the tank, diluting the tank and sending more water down below.
A few hours of this means disaster.
When I got to the tank, it had overflowed perhaps 15-20G of water onto the carpet downstairs and my salinity was at 1.013. Egads!
My steps were as follows:
* Identify backup with filter
* Siphon 3 gallons of water from the tank to buy time
* Turn off RO
* Test salinity
* Reel in shock and horror
* Mix lotsa salt with the 3G of water
* Remove clogged filter
* Remove addtl water
* Restore water from super-salty mix.
* Spend the next 2 hours cleaning and adding super salty water back to the tank
* Few hours later that night I had the salnity back up to 1.023 or so.
* For the next 2 days I let water evaporate to get it up to 1.025 which is where it was when it all started
Amazingly enough, everything seemed to survive. Frogspawn, anemone, crabs, snails, brain, leathers, gorgonia, zoos, mimic tang, jawfish, banggai. Hardest hit appeared to be the Xenia. One stalk over the next couple days disintegrated. The others are still in recovery. The Mimic tang died 2 days later. Everything else seems fully recovered. Amazing.
Just thought I'd share.