healthy Yellow Tang and Sailfin Tang died overnight

[bibiu09]

hello everyone
I am writing as I am very sad. My 2 lovely tangs have passed away overnight (+1 cleaner shrimp).

I had the 2 tangs for 4 months. And they have been through so much! I bought them in a tiny 40 gallon full setup tank, water parameters were rocketing (nitrates as high as 80 etc). Yellow tang came up with ich, put him in a hospital tank treated with hyposalinity and made a full recorvery.

Now, Over 3 months I am running a 100 gal tank, all water good considering what tangs been through where i bought them from. (0.25 phosphates, 2 nitrates, 1.025SG, ph 8.00)

Last night at 10pm, all fish were happily swimming around, healthy and eating well.

I woke up the next day, sailfin was on the bottom of the tank,dead, and my yellow tang actually jumped out of the tank!!

My clownfish was also on the bottom of the tank but breathing heavily. All my other fish (7chromis, damselfish, firefish, cleaner wrasse, 2 gobys) were fine.

Desperately, i checked water parameters, all fine but ph was7.8. I imediately put an airstone in, half an hour later, clownfish was absolutely fine, to this day (2 days after the incident).

Could lack of oxygen in the water be the culprit? My tank is not covered, and i Have powerheads running + powerful skimmer which I switch off at night. No sump. Water changes everyweek, and I top up with RO every 2 days.


I would appreciate your help as I am planning to sell everything and leave the hobby, as I am very affected by the incident. I really loved the tang pair, especially as they were very healthy.

[Sk8r]

Oxygen is suspect---tangs use more than the other species named. Stray voltage would be, except everybody else is ok. I would say you could cure this with a sump and a much stronger circulation, something that causes the water to fall and churn on its way through. I'm very sorry. Most of us in the hobby any length of time have had this kind of heartbreak: I lost 5 large freshwater angels I'd had for years and safely transported across country by car---night before their tank would be ready, the pump failed while I was out at supper. I hope you will stay with it, however, as someone who cares is somebody who will ultimately do well in the hobby.

[Chris Lakies]

Why do you switch the skimmer off at night? What type of water movement do you have?

I would assume that the water wasn't oxygenated enough.

[thegrun]

I am very sorry for your loss. First off, and I'm sure you don't want to hear this, but your tank is just too small for keeping the tangs you had, particularly the Sailfin. Because the tank was too small, when things went bad and they didn't have sufficient room to swim, naturally they were the first to die. As to what went wrong it is difficult to say without more information. Did you have an ammonia spike? It may be too late to determine this two days after the fact, but if there was some type of sudden die off in the tank ammonia poisoning could be the culprit. A lack of oxygen (and your low pH would be antidotal evidence of this) is also a likely cause. The reason tangs need large tanks is that they need to swim long distances to get oxygen, their gills are not nearly as efficient as other fish that can sit nearly stationary over a reef, tangs are open water swimmers. Did anything change in the tank (skimmer stopped running...) or in your home (did you have a fire in the fireplace that could have increased the CO2) in your house? Lastly have you checked for stray voltage? Major losses like yours can be very discouraging and I truly feel your pain and frustration. The best advice I can give is to learn from whatever it is that went wrong and move on from there. The lows in this hobby can be devastating, but I still feel the rewards outweigh them.

[thegrun]

Opps, I see that you do turn off your skimmer at night, so a lack of oxygen would be my #1 guess as too the cause coupled with fish that were not suited to your tank, again, sorry for the loss.

[bibiu09]

Thank you everyone.
Tank was cycled 7weeks before first fish were added. And not sure if amonia spike would have gone in few hours. I have done all tests immediately after I discovered.
When I got the tangs like I said they were in much smaller tank (owner had them for at least 7-8 months) I would say they were small to medium Size but definitely not babies

Powerheads are for 120 gal and skimmer for roughly the same. I keep the tank in my room which is big but the protein skimmer is loud. The tank I bought the fish with didn't even have a protein skimmer on.

The only indicator that lack of oxygen was the problem is that my clown fish made full recovery after an airstone ws put in.
I am only thinking that my power heads left me.

P.s yellow tang was on top of my tank!

[Sk8r]

Has to be the oxygen. Skimmer and pumps must run 24/7, sometimes with additional powerheads or as aforementioned, a waterfall to churn the water. That 100 gallons will support one tang of the smaller varieties, with all the above, and somewhere in the stickies is a recommendation of tangs for what tank size: increasing your skimmer size and bubble-power might stretch that just a little. They're an engaging species. It's my sense that there was a temperature rise (which lessens oxygen) and the tangs in question and all the fish in general were increasing in size and oxygen need. The demise of the tangs likely saved all the others.

[bibiu09]

Thank you again to everyone.
I am now 100% sure lack of oxygen was the killer. It was a sum of different issues that lead to this. Obviously I am to blame for taking things for granted.
I am gutted I was very attached to my tangs, the sailfin used to come on top of the tank when I was feeding and many times he would just swim around my finger and I would stroke him. Such a lovely fish. I am definitely not replacing, might just downgrade tank, keep equipment corals and clown fish and leave the lovely tangs to the experienced. I do not want to make such big mistakes again. I shall visit my local lfs from time to time and watch the tangs swim happily.

Thanks again for your honest comments

[m0nkie]

or upgrade get a 200gal and raise some tangs!

[SwampyBill]

First off, welcome to Reef Central! Sorry for your loss; we've pretty much all been there at one time or another. I lost all 5 of my favorite wrasses a few years back due to stoopid mistake of using carpet cleaner too close to tank. As others have said, stick w/ this amazing hobby, & instead of downsizing, upgrade when you can & get more tangs. Good luck!