Tank Water Problem ?

[Bongobus]

hi,
can anybody help, i have a aquaart 60 litre tank and have had it for about a year. My problem is, every time i try to add new fish, they die. I don't know if i have a disease and my fish supplyer said it could be fin rot so, i treated the tank with melafix and some of the fish are still going but my problem has been going on for about 4-5 months and i am losing heart and i just don't know what to do next.
Hopefully someone will reply and i can get it sorted!!
Many Thanks.

my water sats are 0 and have been for a long time, I am doing a water change of about 20% as that is what my lfs recomended i do.I do this about every 2 weeks, The filter is the tetratec easy crystal filter that came with the tank and I have 3 guppys, 3 danios and 1 white cloud mountain minnow in the tank my ph is 8.2

 

[scooterchick]

You're pretty much at full capacity and I reckon you shoudl be changing water more frequently. You need specific stats, amonia, nitrite and nitrate. I suspect your nitrate is high and your current fish have adapted but new fish can't cope, hence they die.

Before adding any more fish (which I would recommend you don't) get a test kit and get some proper stats. Your PH is quite high as well, what could be causing that?

welcome to the forums! Stick around, you'll get great help and advice here x