Ugh.....time to post an update. Unfortunately, last year I had a major tank crash while we were on vacation - precipitated by a failure of my ATO pump. The resulting spike in salinity and crash out in alkalinity (I use kalk in the topoff) killed a couple of acropora colonies....and triggered a slow but nearly complete crash of the system. There's no point in posting a picture, because the tank is mostly empty. The Tridacna maxima survived, along with a few hardy SPS, soft corals and fish. However I lost all acropora, monti caps, and most LPS. I only bother to post now, because I finally feel that things are under control again, and the system is beginning to recover.
There are always lessons learned, even after many years of experience. So, here is what I think I've learned this time:
1: First the obvious - better ATO system, tank sitter when I'm gone, etc.
2: I'm not buying more coral until I have TWO healthy reef tanks, as an insurance policy (for everything except a power outage, anyways). It's just too much to lose everything. I've had crashes before, but never before lost ~80% of my livestock in one event. The crash was pretty slow - most of the corals died 2-6 weeks in, and I feel many could have been saved if I'd had a healthy backup system to move them to. I guess I'm just happy they were not mature colonies, and that I didn't fork over the money for that homewrecker frag I wanted last year.
3. Skimmerless tanks work right up until they don't (or something like that). The system ran great without a skimmer before the crash, but I was unable to right the ship without putting a skimmer back onto the system. I struggled for several months without a skimmer, reducing feedings, regularly removing algae, and adding snails. This failed, and I had much worse algae than when I started - a mix of cyano, dinoflagellates, and hair algae. During this time, N levels increased, P was basically undetectable at the PPB level, and corals were bleached / starving. Adding the skimmer really tipped the balance, I was able to start feeding heavy again, and the surviving corals have finally stopped receding.
4. Flatworm exit is toxic to snails at the normal dose level. A little bit off topic, but worth mentioning. So I found this out because I tried using it as a 30 minute preventative dip for new snails, only to have some of them die off sporadically after several weeks. Had I only done this once I would have never blamed the FW exit, but I dipped many snails from different sources, and the problem went away when I stopped dipping them. Sorry snails, I didn't know better.
So I'll probably post a photo once the tank doesn't look so awful, but for now it's just therapeutic to try and learn from what went wrong.
Happy reefing,
Steve
