I have a 90ltr tank set up for a small set of apisto.cacatuoides triple red. I bought a pair from a LFS last monday, male looked stressed and didn't make it through the night, female looked fine as did the 1 cardinals I have in the tank, so i went ahead and ordered a new pair (mail order, had there stuff before very good). male from them didn't look too great when i got them, on wed, by sat he was dead, since sat I have lost all but 1 cardinals and a female cac.
Is this a bacterial infection? I'm gutted this was the first time keeping these been planning the tank for months to get everything right.
food was bloodworm, daphinia and pellets broken up, fresh garlic and pea's also feed.
Tanks readings, ph7.0, kH 2, ammonia 0.0, nitrite 0.0, nitrate 0.0. temp 25c, 30ltr water change every 7 days.
is there likely to be residual bacteria in my water from an infection, if it was that? anyway to stop this from happening again?