Never had a crash but I have lost fish and corals that really hurt emotionally. First I find out what I did wrong so that it doesn't happen again. I correct the problem (usually tank maintenance in the case of a coral) and start a new project to get the tank ready for a new form of life I haven't kept before. I clean the tank, do a water change and make sure everything is healthy and happy and the water is nice and clear. I research the new lifeform I will add soon and make minor changes in the tank (lighting, flow, food or whatever) to make it most comfortable.
I think the last few fish I lost ate kalk paste that I put on an aiptasia problem. Stupid fish are used to being overfed and eat whatever goes in the tank which varies a lot from day to day. Two of the fish that disappeared within a week of the kalk incident had been in there for over a year and the other two I lost were new additions that had only been there for about two weeks. All of them took food from the surface, middle or bottom of the tank and my four Cardinals that only feed on the surface were not affected at all. The fish that I lost showed no sign of disease, just died suddenly within days of each other.
My actions after my loss were to do a water change and I didn't really need tank cleaning since it had just been done two weeks before when I added the new fish. I decided to never again use Kalk paste on my huge aiptasia problem. I had been studying Berghia Nudibranchs for a couple of years and wanted to try and raise some for quite a while so I decided that would be my next new project. Not having the cash available for the nudis put a hold on it. Two weeks ago a friend in my local club called me to offer a small adult he found in his tank that had survived on the very few aiptasia he had left. Hoping that it was holding fertilized eggs (they are both sexes but need another to fertilize each other) I set up a 10 gallon with some small aiptasia scraped off the glass of one of my other tanks. My friend had already fed it until the next day when I was able to pick it up but it still ate constantly when I put it in the new home. The next day my friend called again to tell me he had found a full grown adult twice the size of the first one so now I have a pair I have seen breeding.
My point is that my loss still hurts as it does for all the poor animals and plants that have died in my care in over 45 years of keeping aquatic life but I never take the chance of sitting there long enough to get so depressed that I quit. I start something new to keep the interest fresh and the diversity of life in saltwater provides enough projects that none of us will live long enough to run out of new things to do. It doesn't have to be a huge project costing a lot of money that I don't have, two free nudibranchs and a 10 gallon tank I already had has me as excited as I have ever been about a new journey in our hobby.
