Help something is killing my fish

I have setup a 1.2m tank and I have started to put the fish in and so after I let it cycle for a while

I added 4 white angels (small)
20 neons
12 pearl Danios
1 red tail shark
1 siamese fighter
6 Panda corries

but over the last 2 days I have lost 4 corries, 2 white angels, 1 black angel, 3 neons and my siamese fight has almost no fins left.....

is this a disease or is it possible that the bigger black angel is coursing all the problems? because it is more than double the size of all the others.

 

Check the water parameters dude. Does the dead fish look like they were being chowed/attacked?
They could have been nibbled after death.

 

Could be the angel or the red tail shark ... both agressive when bigger than tank mates

 

or a nitrate overload? thats a big bio load to add to a new tank..

 

They were added over time not all in one day, I would say over a week.

and some of them had nipped fins :wondering:

 

I'd check your water parameters first. I agree with Eskimo - even if the fish were added over a period of a week that is still a large additional bioload added over a short period of time. How long did the tank cycle for before you started adding the fish??

I doubt it is the angel causing any havoc as I have never seen a fish attack a cory before, they tend to totally ignore the cories.

 

agreed with eskimo

 

IT cycles for about 3 weeks

they were doing fine till sunday night
then all the trouble started

I will do water testes now now and will let you know

Could it be Dannios?????? I know it might be a stupid question but some one told me that it is possible

 

i have read a tank can cycle for up to 6 weeks , did u do anything to "kick" the cycle of in the beginning? I would tend to agree with eskimo thats alot of fish for a short period and maybe it took till sunday for things to build up and go wrong

 

If I can add to gareth the smaller angels had nipped fins when they were alive so it must be bigger fish like the red tail shark
I would also agree with veegal but the bigger black angels tend to be more aggressive because they already established their territories

 

Yes the smaller Angels had nipped fins before it dies the only type of fish that had not died yet is the Dannios that is also why I wonder if they might not be the reason for the problems because they were also the last to be added
Is it true that dannios are part of the Cichlid family?

 

Test results of water:
Temp - 27 deg
PH - 8.2
NO2 - 0.1 Nitrite
NO3 - 0 Nitrate
NH4 - between 0 and 0.25 Ammonia

Please let me know if this is right for the tank

 

Nitrite and ammonia. Are you softening the water with anything?

 

NO How can I do that?
Are the rest right because I am a bit worried about the PH

 

No as far as I know, Danios are in the Rasboras family, not Cichlids. And they are very peacful fish. Totally unlikely. This leads me to think it is either water quality or disease related. Danios are known as some of the most robust fish and can survive in poor conditions. They are often used to cycle a tank.

How did you cycle your tank? 3 weeks is a little short and if you don't "feed" the bacteria during this period with ammonia or something that decomposes and creates ammonia, then the cycle may never even start.

 

What I did was I started the cycle in the tank with some filter media that I had in another tank and the next day I added a few Mollies(4) to start things off. is that right?

Mollies were removed after 3 weeks because I did not want them in the tank

 

QUESTION will it help if he took some of his own filter media and put in the tank so he gets some bacteria in if like laure said that the cycle may not have started
SORRY DIDNT KNOW YOU DID THAT

 

Any traceable levels of Ammonia and Nitrite can be deadly. You can use RO water or peat to soften the water. Not sure if the fish listed would survive in such alkaline water

 

Danios belong to the minnow family, Cyprinidae, pronounced "Sigh-prin-id-ee", they are are fairly hardy fish and I'm not surprised that they are the only ones that survived.

 

0.25 Ammonia and 0.1 Nitrite, although slightly dangerous, is not enough to kill those fish. In any case, you'd notice them looking really uncomfortable and breathing heavily. Go google ammonia poisoning or nitrite poisoning and you will probably find your fish didn't have those symptoms.

However, Nitrate of 0 indicates that your cycle is not complete, or even near complete. Unless you really know what you are doing and you are very comfortable with water chemistry, I wouldn't advise you to mess with the ph. Most fish can adapt. If the ph was an issue, it was more likely acclimatization shock if they, for example, came from a low ph tank when you bought them. Always good to ask the LFS the ph of their tanks.

So I have some other questions:
1. How long have these fish been in this tank?
2. How many water changes have you done?
3. Did any of them die and you didn't notice in time? Like maybe only 3 days later?
4. Could it be that you didn't add dechlor to the water?
5. Perhaps we can now also suspect finrot fungus?