Tank Crash - help needed.

[oysterboy]

I just came back from a weeks vacation to discover my tank had crashed. I lost all my corals and half of my fish. The other half are not looking to good but may survive.

Basically what happened is a thermometer in the sump broke (came apart in the tank) and flipped a fuse which then turned off my main pump back to the primary tank as well as my skimmer. Given the condition of the water Im guessing it happened shortly after I left and unfortunatly I didnt have anyone to look after it while I was away. My mistake...

I had a backup thermometer in the main tank but it wasnt enough and the temp dropped to 69 and with no skimming the tank started to die. Ammonia was through the roof when I tested with several dead fish and all my corals, and clam gone...

I only recently upgraded the tank with new live rock and a new substrate about six weeks ago. I was still waiting for things to appear on the rock and had noticed a couple of corals and small feather dusters etc which are now gone.

So I have a question:
Given the drop in temp and consiquences can I assume I killed off most of the good stuff on my live rock and will therefore need to purchase some new live rock?

I was planning on rinsing the substrate with fresh RI/DO water to clean out the bad water traces. I thought I might be able to reuse some of the existing rock at the back if I cure for a couple of weeks in a separate tank to clean it.... thoughts?

[rluix]

Hmmm, i don't know about that, my tank dropped from 82 F to 74/72F some days ago, because the lights wen't off for 5 hours, and everything survived, even the corals, and the rock's still alive.
But 69, sounds indeed very cold for a reef, let's see, how much time was the tank in that temperature?

[ToddTT]

I wouldn't do anything right away.

Have you gotten the ammonia under control? If not, are you able to relocate the remaining fish?

Once the tank is stable again, I would evaluate your "live" rock at that point. If it doesn't seem to have any signs of life, you might purchase more rock to seed what's left in your tank.

It also depends on your goals for the rock. "Not-so-live" rock serves several purposes as well.

Good luck.

[Parrothead]

Actually, I'd be thinking real hard about doing about a 50 - 75% water change and soon, go through some of the sticky's in marine fish health and care section, Lee has some good advice about this kinda thing.

[oysterboy]

Thanks for the suggestions.

So heres the latest. The tank was so dead that I decided I needed to get the remaining fish out as quickly as possible. Im guessing that during the night the temp could have dropped as low as 65 and I think things must have been like it for 4-5 days.

I set up a small 10 gal tank (the main tank is 65gals) and got my fish in there with new salt water at the same temp as the tank. I then brought the temp back to 80. Those fish are all looking good now so I think there going to make it.

Since every coral died (about 7) in the tank I took out the rock and emptied it of water. (The ammonia was so high I didn't think there was much point in waiting for it to come down). I then sifted the sand to remove larger debris and a lot of bristle worm (both dead and alive) that had accumulated. The sand now looks clean and Ive started adding new salt water back.

Once I have the tank full Im going to run the skimmer with the best pieces of the existing live rock that are left.

Im then planning on getting a batch of new rock to help stabalize the tank and seed the old rock and start things off again.

Once the water looks good I'll begin reintroducing the fish...

When there all settled I can start thinking about corals again. Its gona take some time.

[ToddTT]

Did you rinse the sand like you said you might? I'm actually hoping for you that it still had some life in it. If you only sifted it clean, maybe there will be some survivors.

In any case good luck, and now you get to fight ammonia buildup in your holding tank!

[Parrothead]

Did you rinse the sand like you said you might? I'm actually hoping for you that it still had some life in it. If you only sifted it clean, maybe there will be some survivors.

In any case good luck, and now you get to fight ammonia buildup in your holding tank!

Also keep an eye on the water parameters of the display, after stirring the sandbed you are gonna have some die off in there as well, be ready to do some water changes on the dt as well as the holding tank.

[Bloodydecks]

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