Adding New Fish Causes Old Ones To Die :(

[Dextersmummy]

I wanted advice if possible. I have had my aquarium set up since last Aug and am geting there with my fishes. Have a tropical set up with gourami and tetras guppies and mollies a fighter and swordtails all doing well. I want to add more of each species tho everytime I seem to add some I loose a old one. Normally a Guppy. I added four pink skirt tetras, four guppies and two loaches then a few days later lost a old Guppy id had a while. Its happened a few times before. I float the bags and let the water into the tank tho koi joy is a wonderful shop popular and trusted so I don't think its the water. Any ideas what I can do? Next wed they are getting more tetras in I want tho don't know if its a good idea to add them? Any advice? Thanks x

 

[phoenixgsd]

how did you cycle your filter, fish in or fishless? was it able to cope with the extra bioload by adding  the four pink skirt tetras, four guppies and two loaches all at once, it might have been a sudden ammonia spike, fish in cycled filters sometimes have to play catch up, how big is your tank

 

[N0body Of The Goat]

Adding newly purchased fish straight into your main tank is like playing "Russian Roulette," eventually odds will catch up with your fish and a newly introduced specimen will bring a lethal bullet to your whole community. Keep new fish quarantined for 3-6 weeks, a basic plastic tub can suffice to keep costs down (although obviously it need filtering with cycled media and possibly a thermometer), not only can you monitor/treat any disease but it means these often semi-staved fish can eat stress free for a while and be in tip-top condition before joining your community.
 
How big is the tank?
 
How was it cycled?
 
Be careful on your fish combinations: Mixing Betta with Guppies can end up badly for the livebearers; mixing a gourami with a Betta is not a good idea and could go either way; {dye injected Pink} Skirt Tetras are infamous for being nippy fish and they will bite at flowy fins especially.

 

[Dextersmummy]

Thank u. All my fishes so far have all got on really well no one seems to bother my fighter and he seems as docile as they come. So I have to quarantine all the ones I buy? Aww that's gonna be hard. The place I get them from is really good and well known does that not matter? X