On Wed, 17 Aug 2005 21:09:32 -0500, "Connie"
wrote:

Ok - so I successfully cycled my tank, and got new fish. This was 11 days
ago. Well - I got home from work yesterday, and all but one of my fish were
dead. They were all fine before I went to work (my angel is the only one
left alive). They have been seemingly ok for the last 11 days.

My ammonia did a mini spike up to 2, but I have managed that with water
changes and ammo lock. It was only one day....

What in the world happened??? What could it have been that 3 corys, 2
swords, 2 gourami, and a rubbermouthed pleco all died at the same time, with
no warnings signs...

My ammonia was 0 - .25 when I found them dead.

Thanks,
Connie

I suggest that you give up, on the fishless cycling I mean. Change out
a large amount of the water to dilute out ammonia, nitrites, nitrates
that might be there now. Keep the one fish you have, and cycle the
tank with that fish. Depending on size of tank and which fish you have
you may want one more fish or a couple more, most likely of the same
specie (but this depends to some extent on which fish it is).

Use dechlor, dechloramine, de-heavy metal water conditioner of some
kind on your tap water you're adding. DON'T USE anything else of any
kind when you add the new water: no stress coat, extra-super-enzyme
crap or aloe vera hip hooray stuff or anything else whatsoever. No
carbon or any other chemical type purification stuff in your filter.

In the coming weeks you're monitoring the ammonia, nitrite etc. Maybe
you see some ammonia, then you register some nitrite, after a while
these both go to zero, and you're seeing only nitrates. So then you're
thinking: "I'm done! My tank is CYCLED!!" Well...think again. It
isn't. It is cycled for that one fish, or three fish or however many
you have right then. If you add ten more fish in one day, suddenly
there's three times as much ammonia being produced as the day
previously, and there are enough bacteria to consume 3 fishes worth of
ammonia, there are not enough bacteria to consume the ammonia from 13
fishes. So you get an ammonia spike; and after that you maybe get a
nitrite spike. And blah, blah...you're trying to cycle your tank
forever.

So what you do is: you "cycle", supposedly, the tank with this fish,
or a few more (depending on the specie). When your ammonia is at zero
and your nitrite is at zero a few weeks from now, you put a very small
number of more fish into the tank, a couple weeks after that you can
add a few more, a few weeks after that some more, etc. You add the
number of fish slowly and surely and the number of bacteria consuming
ammonia and nitrite is increased slowly but surely. A few short months
from now you have a fully functioning happy tank with healthy
inhabitants. It's easy.

-Derek