fail again - another fish died

[rBlair]

I've had no success getting fish through QT. The best I've done was my last attempt that failed tonight. I had a powder blue tang in the QT tank for almost 5 weeks. It was looking and doing great. This is a bare bottom, pvc pipe only tank. The tank was fully cycled. I did a partial water change (as I have done every week, about 5 gal out of 20 gal tank) but the tang immediately went into distress when I turned the filters back on. Swimming wildly then finally settling on the bottom leaning against the side of the tank. Stopped moving about 10 minutes later while I was trying to figure out what happened.

The water is RODI I ran Thursday. I mixed the saltwater tonight in a rubbermaid tub for about 3 hrs with a heater. I also used some of the same RODI water for 2 freshwater tanks minutes before and those tanks are fine. I actually made enough saltwater for the QT tank and another 5 gal for my 20 gal observation tank which I did not do the change in. Did not use any de-chlorinator since it had set for 2 days.

Tested water and ammonia, nitrites, nitrates all 0, PH 8.0, temp was 78, as in the tank. Salinity was matched to tank at 1.025 (Milwaukee digital)

The salt was from a brand new 200 gal box. One bag poured into a 5 gal bucket for storage, stirred some before use.

The only things I can think of are there is an issue with the salt, but I realize that is probably a low risk, or somehow something got into the tub I use to mix since I had just used the same bucket for freshwater twice so anything should have been rinsed out.

The buckets, tub, and brute can are used ONLY for tank care

Any other possibilities? Is it generally this difficult to stock a tank? I had hopes of getting my 75 gal (been cycled for about 5 mths now) stocked so I can start planning the 180 I am cycling but now I question if I will have fish in these tanks

 

[thelawnwrangler]

Temperature change?

 

[rBlair]

no, temp was the same as the tank with a digital thermometer

 

[ChadO]

Were the brands of salt the same? You mention a new 200 gal box. Is it the same brand of salt that was used and already in the QT tank?

Also, what are you using for filters? Reading your post, it sounds like you successfully completed the water change, and the tang wasn't showing signs of distress. It only started swimming wildly after you turned the filters back on. It seems like if it was purely in the new water, that as soon as you got a decent amount of that new water in the tank, that if it was contaminated, that the fish would have started showing signs of distress before you put your filters back on. Does that make sense? What is really curious to me is that the trigger here seems to be the filters coming back on. Maybe the act of turning them back on caused something toxic to come out of the filter? Something along the lines of anaerobic related? I'm just trying to toss out ideas that maybe someone can run with. I just feel like focusing on the filter and related stuff with it might be a place to start. If that water was really contaminated, it doesn't seem like it would have needed the assistance of the filter to cause the issue - just pouring it in should have done that.

 

[dragonsong]

Maybe you scared him to death? I had a coral beauty in QT, when I turned on the lights in the morning (not even too fast or too bright) she absolutely lost it and spazzed around the tank crashing into everything and dying the next day.

That's the only thing I can think of as my fish appeared totally healthy till that similar incident. Maybe cyanide poisoning? That's my other guess.

 

[A.Astore]

Getting that first fish in can be the hardest part. I was there, thought the same thing. I know you said you had this particular one 5 weeks, did he ever act like this when you turned the filter back on before? I know for my QT once they are through the TTM which doesn't need water changes since the water is changed every three days, I do small water changes that allows me to leave the filter on while doing them. The fish could have been stressed enough and the addition of the startle was enough to do him in. Maybe he ran into something in the process of being startled even. Do you have anything in your filter as far as media that was changed out?

Where are you getting your fish from? I don't know that something caused an issue this time that would be related; however, the first ones may have been related to handling prior to you getting it. Also, do you treat for anything or do you do a longer monitor type QT? There are some parasites that can cause issues less noticeable but eventually cause a fish to die unexpectedly.

This is all stuff that potentially could help to narrow down what it could and could not be overall.

Trust me, I was there. I almost threw the towel in and went all coral/invert because I had such a heck of a time initially due to the health of the fish I was getting in. It is never easy to have a fish die but it is even worse once you get to the point you think you are going to be good.

 

[rdnyva]

Sorry for your loss, it's never easy.

A little off topic but maybe you should start with an easier fish than a Powder Blue.
Also, I wouldn't make a PBT the first fish in the tank.

 

[Sapelo]

I agree with rdnyva, PBT are not first fish and not a fish for a 75 gallon.
Start simple.

It's also unlikely that the fish died from a water change (especially since you'd done water changes previously) unless you are really missing something about your water quality.
My bet is on something being wrong prior to the water change.

What is your general QT procedure? Did you treat for/with anything or was this strictly observation?

 

[rBlair]

all great ideas and questions -

for filters I am using a fluval 50 with sponge and ceramic rings, and a whisper 50 with just the plastic comb.

this tang went thru TTM that included prazi pro, then into this tank. my plan was to put it into the 75 while I stocked the 180 then put move it from the 75 to the 180.

I have always turned off the filters when doing the water change it never acted like this before. But I agree that is seems linked to the filters coming on.

The salt is Instant Ocean and thats all I've used.

Got this fish from the LFS, others have come from the same or another LFS, and a couple from the petco.

 

[A.Astore]

One last question since nothing stands out as being obvious in your responses.

What are you doing with the media you used for the prior fish? Are you reusing it without sterilizing it? And did you use the same media during TTM?

 

[TimeConsumer]

Did you check the pH or alkalinity of the newly mixed saltwater before you put it in? That's a step I liked to take, because sometimes you can get a bad batch that is low on alk. Or if the salt has settled too much it gets out of whack unless you roll it around and mix it up.

 

[Sk8r]

The oxygen demand of tang species is very high. I would suspect that 20 g qt is not large enough and the oxygenation of the filtration is not enough.

 

[rBlair]

One last question since nothing stands out as being obvious in your responses.

What are you doing with the media you used for the prior fish? Are you reusing it without sterilizing it? And did you use the same media during TTM?

no filters in the TTM tubs, just an airstone that I toss after use. This tank is only used after they complete the TTM process

 

[rBlair]

I did check the PH, it was 7.8 in the new water an 8.0 in the tank. Still read 8.0 after the addition of the new water. I don't have an alk test, looks like I'll be getting one.

I'll avoid the tang and more difficult fish for a while, maybe I can get some hardier fish in the tank.

thank you all for the help

 

[scooter31707]

How old are your filters on your RO/DI system. Do you have a TDS meter? I thinking it may been the water. Freshwater fish can tolerate more than saltwater. when you get a chance or make your next batch of water just check it.