"Nemo" wrote in message
...

gH = 3
kH = 3
Temp = 79-80 oF
pH = 7.8 - 7.2 (over a week say)

1-2 x 25% Water changes weekly
Tap water
gH = 3
kH = 2-4
pH = 8.0-8.2

Symptoms - dead neon tetras

First thing to check would be ammonia, nitrite, and nitrate.
Especially with your high pH, any ammonia will be present
in (highly toxic) molecular form, which could be the cause
of the deaths.

Cheers,

Michi.

--
Michi Henning Ph: +61 4 1118-2700
ZeroC, Inc. http://www.zeroc.com