Fish keep dying, but corals are fine.... why?

[csrobe02]

I have a 20 gallon tank and I have been VERY unsuccesful keeping any fish in there. I started with 2 clowns and they lasted about 3-4 weeks and then just died out of no where. After they died, I then got a yellow watchman goby and had him in there for like 2 weeks to make sure he was doing ok. After I was sure that he was fine I went and got a sixline wrasse. The sixline died the next day, and about 2 weeks after that the yellow watchman goby died.
Ive tested my water and it tests fine, but the water is a constant 76, is that too cold? Also im only running 1 maxijet 400 in there, could it be due to not enough water flow?
I just dont understand it, because my torch coral, open brain, zoos, mushrooms, candy cane, and xenia are all doing awesome.
Anyone have any ideas on what it could be??

 

[sebae0]

how long as your tank been setup? also fill in some more of your water params and i think we will be able to help you better.
acclimating process? and some other info needed . hth

 

[csrobe02]

Sorry bout that.
Tank has been setup for about 4 months with about 40 lbs of LR from this site, 3.5" sandbed with about 2.5" of playsand from HD (not its not southdown) and 1" of live sand from this site on top of that.
Im at work right now so I cant get the exact water params. Ill put them up later tonight.
But as for the acclimation process I do the drop method. I put everything in a tupperware container and slowly drip water from my tank into the container. When the container is full, I pour about half of the water out and repeat for about 1 hour. The thing that I might have been doing wrong was I never turned my lights off when I introduce them into the tank. But I figured stress could not have killed them because I had the clowns and the goby for like 3-4 weeks before they died, and they seemed healthy.

 

[beerman]

I would raise your temp about 6 to 10 degrees. Not sure why it's not hurting the corals.

 

[beaslbob]

I didn't have corals but had very similiar problems with my 55g after about 3-4 months. I think that was due to ph problems. My ph had dropped to 7.4. Sometimes I would lose 4 of 5 new fish in a week. With additional running the ph is now 8.2 - 8.4 and the few new fish I have added are doing fine.
I also started adding plant life. If you do not have plant life I highly recommend you add as much as you can. whatever is killing your fish will probably be corrected with plants.

 

[fshhub]

lots of plants are asking for more than you can imagine, at least in the main tank.
I would start off by posting the parameters, and what test kit you are using? Double check the date on it as well.
also how long have the corals been in it? it takes a long time for a coral to actually die, most will seem to be doing fine for even months before they actually die

 

[jmesmcm]

The tank being 76 degrees should be fine as long as it is not swinging by more than a degree or two either way. I keep my tank at 76 and all the corals and fish are fine in it. Goodluck.

 

[csrobe02]

Alright, more information. I just got finished testing my waterand here are the water params:
Nitrates: < 10
Nitrites: 0
Ammonia: 0
pH: 8.2
Salinity: 1.025
Temp: 76
Calcium: I lost my booklet for a red sea test kit, but I used 6 drops for the liquid to turn orange, if anyone knows the conversion.
Some of the corals have been in the tank for about 2 months (open brain, hairy mushrooms, zoos). The hairy mushrooms have gotten HUGE, the brain looks like it is doing very well opening up very large, and the zoos all open fully. But today when I got home I noticed a head on my torch coral is not fully extended, its half way sucked into its skeleton.
ugh, this hobby can be so frustrating some times
EDIT: Oh yea, the test kit that I am using is FasTest, and it expired in 2005

 

[bdhough]

All your water params seem fine. It could be that a parasite is in your tank. Do you notice anything wrong with the outer bodies of the fish when they die? Any kind of spots or anything abnormal looking. Parasites can stay alive in a tank for 3 or 4 weeks without a fish host and as soon as you add a new fish it very possible for the parasite to restart that life cycle every time. Giving you your fish deaths. If you don't have any fish at all i would suggest letting the tank sit for a month fishless just to make sure whatever it was works itself out.

 

[csrobe02]

Alright, that would seem best. Does that rule apply to shrimp also? Because I have 2 cleaner shrimp in there and they seem to be doing fine *cross fingers*.
Will the parasite be able to live on the shrimp? or does it need a fish?

 

[bdhough]

No. It's strictly fish. You just can't treat that tank with anything because it will most likely kill anything invert/coral in your tank..... If there were external parasites then the cleaner shrimp will clean the fish off to some extent. Most likely it was something internal going around there.

 

[csrobe02]

Awesome. Thank you very much. Ill go fishless for about a month and try again, hopefully this time it will be successful
Thank you for your help and advise

 

[luckyk0505]

Where do u get your fishes from??
are u sure u picked healthy and net caught fish?

 

[jmesmcm]

If it is a parasite, a UV sterilizer may also help. When I first started my 37 gallon tank every fish we put in after the cycle was complete had a 6 week life expectancy almost to the day. Finally we added a UV sterilizer and suddenly the fish dying stopped and the tank remained healthier for the rest of the time that tank was set up.

 

[squidd]

FWIW...6 drops on that test kit = 90 ppt calcium...rather low

 

[bdhough]

Squidd red sea is by 50 a drop so i think he has close to 500 calcium..... You add the first 4 plus whatever else he adds....
JmesMcM i agree with you there about the UV sterilizer but he has a reef tank. It's definitely a nono to put a uv sterilizer into a reef. There are to many micro particles of life drifting around in there for all the corals and inverts to use. The UV sterilizer will kill most of that off and cause more harm than good in a reef tank. If he had fish only WITHOUT live rock then it may be much more beneficial.
luckyk0505 also posses a good question. Find out where your store gets their fish and try and find out how that supplier gets THEIR fish. Certain methods of wild catching leave a fish in a terrible state. But my guess is still a parasite in the tank.

 

[squidd]

OK, but his Edit said Fast Test and thats multiply total drops x 15
And my Red Sea kit uses a syringe and a chart for converting the remainder...

 

[fshhub]

calcium, IMO right now is not as crucial as the other readings. although important, it would affect corals long before it will kill fish. esp if the ph and lalk are in line.
my vote is either on parasite or disease of some type as well.
are there any noticable signs, spots on the fish, pieces missing or anything like that?

 

[csrobe02]

Not really any spots, but when my clownfish died, the night before they went to the big ocean in the sky they looked like they had white powder all over them. They did not look good. Ive never seen ich, but it didnt look like grains of salt, it was more like they lost color.
The sixline I think was sick from the store, because right when I put him in the tank he hid, and one day I was just staring at the tank and he came out of the rocks shaking until he turned upside down on the sand with "X's" in his eyes.
The goby just slowly started acting weird. Like, he moved spots from the front of the tank to the rear. never came out when I fed, swimming towards the top of the tank. I dunno.
Thanks again for the help guys, I really appreciate it.

 

[jmesmcm]

I run a UV on my reef and still have more than enough pods and floating particles going through the tank. I have heard competing philosophies on the running of a UV on a reef. Of the 3 high end fish stores near me, 2 run UVs on their reefs constantly and 1 never runs a UV on a reef. In looking at the tanks between the stores I seen no disadvantage to running the UV on a reef and only benefits.