Tank Crash Crisis Management

[ahochan]

After running my 100l soft coral tank pretty much smoothly since its inception almost 5 years ago, disaster has now struck.

I've been away from an extended vacation, and it seems that I overstimated the amount of time my automatic top-off system could run on its own. When I arrived a few hours ago after being gone for three weeks, the entire top-off reservoir was empty, and the sump tank had been depleted so that the main circulation pump had stopped running. The water level in the main tank was normal, so I don't think the tank has been in this state for more than a day or two. Still, it is winter, and the heater was in the pump, meaning that the tank temperature has probably dropped very significantly each night. To add insult to injury, the rotating part of my feeding machine had fallen off and gone into the water, releasing about a month worth of food in one go.

When I arrived, the tank was a bleak sight: All the corals are dead, and the color of the live rock is muted. Two of my three fish are still alive, one seems to be fairly healthy, but my clark's clown seems to have gone blind (his eyes are glazed over, and he swims around aimlessly bumping into things). Some of the clean-up crew is also alive. I've re-filled enough fresh water to get the pumps and the skimmer up and running again, and the temperature has stabilized.

Any ideas on how to manage everything in the most dignified way will be much appreciated.

I have an extra tank I can fill with fresh saltwater, but I'm not sure if I should move the survivors immediately, or wait a day or two. I can imagine that there will be a significant ammonia spike when all the dead material starts to decompose. The skimmer is already running in overdrive, but I doubt it will be able to clear things up quickly enough.

 

[Innovator]

Sorry to hear of such an event. In all honesty, I would just break down the system by having an extra tank to hold fish, drain the system by gravel vacuuming while removing dead coral skeletons and remaining bodies, put remaining fish/coral in the holding tank (use small amount of existing water and acclimate until holding is filled), and refill main system. You will have to keep gravel vacuuming and siphoning until you get stability long-term and may need several 100% water changes. You will probably have to replace your return pump since it likely burnt out.

 

[cmor1701d]

I'm assuming you have the heater and return pump working again.
It would appear that the tank SG was quite high for a few days due to the evapoation. You brougt it back down quickly which may cause some additional stress.

Moving the survivors to another tank while cleaning up this one would be a good idea. If you can bring some filter material from this tank great,, otherwise you will be doing 2x/daily pwc's while the new tank cycles.

Check for deterioration on all your corals and frag those that show signs of disease or are disintegrating. The obviously dead one should be removed asap.

I would do several 30% PWC's over a week which would change out just about all the tank water, without doing a total teardown.

Were you able to remove the food that dumped?
Are you sure it just happened, or did it happen a while ago and the spike is now over?
Have you checked the water parameters?
Please post the current numbers to see how bad it got.

 

[mr_X]

something to add- the amount of evap needed changes with the seasons. i use almost twice as much water in the winter. i suppose it's the dry heat.

 

[ahochan]

I did fill up quite a lot of freshwater in one go to get the pump and skimmer going again. I figured that was the best way to get the system running at correct temperature again. Next time I leave for an extended stay I _will_ add an extra heater to the main tank, just in case.

I'm out of water testing equipment, so I'll need to drop by the LFS today. I'm just guessing, but its most likely that the feeder fell off quite some time ago, and that I somehow did not fasten it properly to its spindle. Most of the food was still inside the box, so I was able to get most of it out.

Its still early here, so the lights are not on in the tank yet, but I see the damage is not as extensive as I thought. All three of my fish are indeed alive, and they now seem quite healthy. I see some hermits scurrying about too, and one of the corals opened up yesterday before lights out.

I normally lose about 1 liter a day to evaporation in winter, and almost nothing in summer. The evaporation amount must have been significantly higher than one liter a day this time though, I guess it is due to the house being colder since all heating was off for the entire time I was gone. (I live in Tokyo, which has relatively mild winters, and terrible indoor heating).

 

[Deep Seven]

Keep an eye on your sump and make sure its not leaking. A slow leak might explain the unusual water loss.

 

[ahochan]

Parameters are:
Ammonia: 0
NO2: 0
NO3: 50 mg/l

 

[cmor1701d]

PWC's to get the nitrates down. Check Al, Ca, Mg and PO4 too.

 

[ahochan]

It seems that all my livestock is alive, and seemingly healthy (i.e. back to their old behavior), so I decided that instead of moving the livestock to the spare tank, I would instead move the LR with the obviously dying coral there. I also did a big PWC, and will continue to do that as long as necessary.

Here's a list of the coral and their conditions:

Moved:
Pink leather coral: I had two of these. A small, recently acquired one, and a three and a half year old one. The three and a half year old one had grown huge, and was towering over the entire right side of the aquarium. It has collapsed completely, but is still showing some signs of growing bigger during the day.

Not moved:
Mushroom coral: They still expand and contract, but to a much lesser degree than before. When I moved the entire tank two years ago, quite a lot of these were accidentally out of water for a long time, and the same thing happened then. They have since recovered, and I'm hoping the same will happen again.

Button polyps (zoanthids): About half of the buttons open up, and look exactly like before. Some are closed, but I do not know if they are dying.

Green star polyps: This mat had expanded to about twice the size since I got it about 6 months ago. All the polyps are now closed, and it looks like it normally does at night. I don't see any signs of decay, so I'm hoping it might open up again.

PS: I have never checked Al, Ca, Mg or PO4 on the tank. I run activated carbon and purigen on the tank, and occasionally add PhosGuard.

 

[mr_X]

all of those corals will be fine. you don't even need to run any phosphate removers, or purigen, nor do you need to worry about calcium or mag IME. just do regular water changes.

 

[ahochan]

A little update: The big pink leather coral suffered a catastrophic meltdown, and fouled up the water in the emergency tank so bad that it looked like milk and smelled like rotten egg. It had grown twice as big compared to when I got it, so its a bit of a letdown. On the other hand, it had grown so big that it was towering over the entire left hand side of the aquarium, so I was actually planning on getting rid of it... not by killing it though

On the plus side, the zoanthids are opening up fully again, and the green star polyp is also opening up, albeit with significantly smaller polyps than before. The mushroom coral are not expanding much, but I guess they just need more time.

The plan now is to let the tank stabilize for a few weeks, replace some of the sand, and then figure out a new layout before forking out for some fresh coral.

Next time I'm gone for an extended time, I will:
* Place an extra heater in the main tank. Not sure why I didn't think of that before
* Double the size of the top-off reservoir
* Buy a new auto-feeder. Any recommendations?