3 fish dead!!

[punch]

I bought 5 marble corries and a ram last sunday. 2 of the corries
died and so did the Ram. (I have another Ram that is doing fine)

65 ga. tank w/ a fluval 404 filler. Planted
Ph 7.5-8
gh 6-7
kh 4
(my co2 diffuser is clogged and needs cleaning)
no2 <.3
no3 0-12.5
nh3/4 0

So what might of killed my fish? Im thinking the PH becouse
my co2 clogged. but I'm not sure.
Any ideas?

 

[carpguy]

Your KH and pH seem wrong. They don't really jive with each other. Where had you been keeping your pH before you lost the CO2? A big bounce could certainly produce some mortality…

 

[punch]

My PH with Co2 is pretty stable at 7, soo....
I guess This week-end I'll get it going again, and do my water change and re test.

 

[carpguy]

The WetMan mentioned something a few weeks back about toxicity and pH levels that I didn't follow all the way through. I know for instance that Ammonia is more toxic at higher pH levels, but in a mature planted tank there shouldn't be enough free NH3 to kill 3 fish. Not really sure what exactly about the bounce kills fish, or why some die while others don't. All the casualties are from the more acidic end of the spectrum. Just seems like a likely suspect.

I've been a little concerned about the same thing happening in reverse with adding CO2, but haven't posted on it yet.

Ambient CO2 I think is around 5ppm, so with KH 4 your pH should be around 7.4 according to this handy chart. But if the plants are consuming the CO2 then maybe the pH can get driven a bit higher. Say, up into the 7.5-8 range. Still a bit murky on the chemistry stuff.

 

[Cichlid Woman]

Since they're so new, I wonder if they suffered ammonia or nitrite poisoning before you got them. Did they spend time at the top of the tank trying to breathe? Were their colors really bright when they died?

-- Pat