I don't understand what's happened!, I've had my tank set up and cycled it for 2 months before adding fish, I had 10 tiger barbs and 5 red eye tetra in my tank, I have been checking my water parameters every 2 days to keep an eye on things my ammonia is always at 0 the nitrite at 0 and nitrate at about 10, my ph is always 8.2 it's high around here, all was well I did my routine water change of about 40% , using de chlorinated water of the same temp, all of a sudden the tigers started becoming shy, then 2 of them where gasping around the top of the tank and just died, I have a big air curtain in the tank so I don't think there's an oxygen issue? My temp is around 27 c all the time, I have just done another big water change just incase , all my red eye tetra are happy as larry, but the barbs just seemed to have crashed, they had been feeding fine I really don't know what's happened?? My tank is 23 gal
Thanks
Thanks