Fish keeps on dying in QT after a week

[scorpio12345]

So i'm just having very bad luck with QTing my fish. I do not want to put anything to my reef tank without Qting the fish but I keep on loosing them after exactly a week or more.
My water parameters are these.
Salinity 1.021-1.023
Ph : 8.2
Ammonia: Non detectable on the Ammonia alert sticker
Nitrite: Not detectable
Nitrate: less than 20
Temp: 80-87F (I live in the tropics so fluctuates around 5-10F within a day)
Primary water movement: Two sponge filters
Water changes: 20% once in a 3 days

Mostly I'm trying to QT Tangs. They eat well and then all of the sudden over night they die. No signs of stress, cloudy eyes, ich or anything. Only mysterious behaviors is they dart across the tank very fast once in awhile and sometimes move head side by side,

I've tried Prazi treatment and non-prazi treatment and then just no treatment. And then tried adding Amquel once in 2 days to control any sort of Ammonia (Didn't do any medications with it) But the fish keep on dying. Same way no symptoms just dead after eating well I get a bit of sunlight on to the tanks so next time I'm gonna try without it.

If you guys can just explain your method of QT fish then I can at least try that. As in how big of a tank for a 5inch Tang, what kind of filtration, how much water change, how many times feeding, medications steps, what is success rate on your qt tanks.

I'm very sorry for the long post but I'm desperate as my tank is stopped at one point because of no additions. And I hate to get more fish and kill them.

 

[ThRoewer]

How big is the QT and how big were the fish?
The sponge filters may not provide enough water movement. I would also add a skimmer.

 

[scorpio12345]

Its a 50gal tank my last naso Tang was around 5 inches. Wouldn't the skimmer suck up medication?

 

[scorpio12345]

How big is the QT and how big were the fish?
The sponge filters may not provide enough water movement. I would also add a skimmer.

It's a 50gal and my last Tang was a 5inch blonde naso Tang.

 

[Reefstarter2]

too warm not enough oxygen for the fish . do they have labored breathing ? Im guessing they do

 

[jamesbaur13]

Are you using Amquel or Amquel Plus? I believe Amquel Plus is not compatible with Prazipro. You might want to call Hikari just to verify.

Sorry, disregard... I just reread your original post.

 

[scorpio12345]

too warm not enough oxygen for the fish . do they have labored breathing ? Im guessing they do

They didn't look as if they were breathing heavily. But perhaps I'll put a shade net on the windows there is a bot morning sunlight coming on to the tanks. My QT setup is outside.

Is there any way I can increase DO without decreasing the Temp?

 

[Perth_reefer]

I've run a QT with tangs in with just a air stone in it in the past. When I do TTM all I use is an air stone and that seems to work fine. I have the same problem here with quarantine tanks in the summer, 30C at night and 45C in the day, almost impossible to run quarantine without a chiller attached to it.

 

[scorpio12345]

Thanks guys for all the input. Hard for me to run a Chiller on it but I will run a power head and a skimmer so more air exchange. Hope it would help out.

 

[Perth_reefer]

Thanks guys for all the input. Hard for me to run a Chiller on it but I will run a power head and a skimmer so more air exchange. Hope it would help out.

I'm not sure if that will do the job if heat is the issue to be honest, I lost all my coral and most of my fish a few years ago when I wasn't as wise about the rapid rise in water temperatures during the summer. On a particularly warm day (about 39C) my water temperature rose to 33C and wiped almost everything out, this is going to potentially happen even quicker on a smaller quarantine tank.
Hopefully the water movement from a power head will help, but that coupled with high air temperatures is going to mean a lot of evaporation so just be prepared for that.

 

[ThRoewer]

If you don't have a chiller, a strong fan may do just fine. It's what I use and so far it worked fine.

 

[JohnnyB in SD]

7 degree water temp fluctuation within 1 day is not a good thing. In my experience is fatal to most livestock. If it were me I wouldn't go over 2 maybe 3 degrees without some concern.
Block the direct sun as you said, use fan like ThRoewar suggests. Keep the entire room as cool as you can, air circulation if not AC.
Do you have high wattage pumps contributing to the issue?
Airstone on a QT for extra oxygenation is a good idea in general.
I freeze some RODI water and drop it in my tanks when not using a chiller. Obviously can't use enough to decrease water temp more than maybe a degree without making bad situation worse by effecting the salinity, but it can help some. I would go about a gallons worth on a 50gl myself. Compensates for evaporation too.
Can also use frozen water in leakproof bags. This can become a lot of effort if you have to do it on a daily basis.
AC unit for the room or chiller is best solution if you don't want to keep loosing fi$h. Loosing my Blonde Naso would be a borderline tragedy for me.

 

[snorvich]

too warm not enough oxygen for the fish . do they have labored breathing ? Im guessing they do

Good guess. Higher temperature equals less dissolved oxygen and lacking a skimmer, this could be the problem.

 

[snorvich]

If you don't have a chiller, a strong fan may do just fine. It's what I use and so far it worked fine.

This.

 

[Giovanni]

If you have a store near you that sells those small portable air conditioners, you could set up a tarp over your tank and use the air conditioner to cool that small space.