We have been keeping mainly tertras for quite some months in our BioUbe tank, and regularly changing filters and water as instructed.
Then 3 months ago, over a matter of 4 days one by one of the fish died much to the horror of my kids. So, we waited for a few weeks, thoroughly cleaned the tank, gravel etc. Then restarted the tank and left it without fish for about 4 weeks. Then re introduced some neon tetras which all died within a couple of days.
Unpreturbed, we rechecked pH levels etc and noticed it was slighly alkaline to popped in a few mollies just yesterday. One died over night. The remaining one looks less than happy.
I kept a lot of tropical fish as a kid, and have never had fish just simply die off in a matter of days. I am getting to the point of throwing everyything away and starting from scratch once again.
WHat pointers does anyone have apart from the usual ones of settling down the tank - which I reckon was done over the last 4 or 5 weeks.