Strange Survival Rate, what gives?

Hello everyone!

I was wondering if anyone could give me some ideas on a problem I have. I
recently bought a pair of Apisto. cacatoides, a Borneo Sucker, and 2 Khuli
loaches, and put them in my tank with my 5 emerald corys and 2 baby
bristlenose cats. Everything seemd fine until the loaches went into a
distressed state the next day and died. The next day I found the Borneo
sucker dead. 3 days later I found the male apisto dead, followed the next
day by the female. This is strange becasue they seemed to be doing fine,
staking caves out swimming together, etc... And on top of that, one of my
bristlenoses died as well.
Gotta be something in the water, right? The really odd thing is that
today I looked and my cories which I have had for 3 weeks spawned and left
pairs of eggs glued to everything!
So obviously they like the environment.
Can any of these things be the cause of my misery?
A) the CO2
B) Some driftwood from the beach (soaked for 6 weeks and boiled thoroughly)
C) Too much liquid fertiliser (followed directions)
D) too little O2?? (how can you tell?) The plants are growing well too.
E) epoxy. used it to glue the syringe to the end of my DIY CO2 reactor hose
so I could put it in the outflow hose of my Eheim filter.
F) Some hardened siltstone that I picked up. No Ca leaching, and according
to my geologist friends, essentially inert in the aquarium. (my cories seem
to have o probs with it either!)

My tank specs:
130L tank (1 month stocked, but cycled for 2 months), with good lighting, a
fair amount of fast growing plants, DIY CO2, EHEIM Filter, fortnightly 25%
water changes and once a week liquid fertiliser dosing. pH 6.8-7.0, no
nitirites, and the other measurements I do not have the kits yet! Temp
steady at 27C.

Any Ideas anyone???

Thanks!
-Seweryn

mediocre meanderings midposted....

"Seweryn" wrote in message
...
Hello everyone!

I was wondering if anyone could give me some ideas on a problem I
have. I
recently bought a pair of Apisto. cacatoides, a Borneo Sucker, and 2
Khuli
loaches, and put them in my tank with my 5 emerald corys and 2 baby
bristlenose cats. Everything seemd fine until the loaches went into a
distressed state the next day and died. The next day I found the Borneo
sucker dead. 3 days later I found the male apisto dead, followed the
next
day by the female. This is strange becasue they seemed to be doing
fine,
staking caves out swimming together, etc... And on top of that, one of
my
bristlenoses died as well.

Certainly sounds like water shock of some type.

Gotta be something in the water, right? The really odd thing is
that
today I looked and my cories which I have had for 3 weeks spawned and
left
pairs of eggs glued to everything!
So obviously they like the environment.
Can any of these things be the cause of my misery?
A) the CO2

Possible, but IMHO, does not sound likely. My understanding is that at
moderate levels, CO2 does not displace O2, and if/when it did, it would
affect fish which were low 02 sensitive, or any fish which lived at the
bottom of the tank. I'm not sure if Corys really fall into this category
as they are able to process atmospheric O2 through their gut when the
levels get too low. The sign would be a lot more trips to the surface
than usual. The fact that they are spawning would indicate some relative
long-term stability, though a spawning trigger is often a small change in
water parameters, so there isn't anything too conclusive there, other
than there wasn't a pre-existing stressor which the Corys could not
adjust to.

B) Some driftwood from the beach (soaked for 6 weeks and boiled
thoroughly)

I would also assume this to be safe, as the parameters needed for it to
be unsafe would be too much of a long shot. Even if the driftwood had
something (ie: residual pollutants, molds, etc), it would be benign
enough for the Corys to have been able to adjust to it, and it would be
constantly diluted by your water change routine. Only if you were
completely stumped (excuse the pun ;~), would you (as a normal course of
eliminating variables) remove the driftwood from the tank.

C) Too much liquid fertiliser (followed directions)

Again, staying within dosages and your water change ritual, I don't see
any vector with ferts.

D) too little O2?? (how can you tell?) The plants are growing well too.

Would be evidenced by the fish hanging at the surface, especially during
periods of the lowest O2 levels which would correspond with the last
hours of darkness if your DIY CO2 is not regulated (shut off during
nightfall or when the pH is too low).

E) epoxy. used it to glue the syringe to the end of my DIY CO2 reactor
hose
so I could put it in the outflow hose of my Eheim filter.

AFAIK, epoxy (the 2 part type using a resin & hardener) is completely
inert.

F) Some hardened siltstone that I picked up. No Ca leaching, and
according
to my geologist friends, essentially inert in the aquarium. (my cories
seem
to have o probs with it either!)

Easy to verify by putting a significant quantity in a pail with some
feeder guppies for a week or 2.

My tank specs:
130L tank (1 month stocked, but cycled for 2 months), with good
lighting, a
fair amount of fast growing plants, DIY CO2, EHEIM Filter, fortnightly
25%
water changes and once a week liquid fertiliser dosing. pH 6.8-7.0, no
nitirites, and the other measurements I do not have the kits yet! Temp
steady at 27C.

Any Ideas anyone???

I would like to know your tank and source water's kH (buffer or
alkalinity or whatever it's called where you live). This might give a
clue toward my first idea:

g) pH, 2 possibilities. The first is that your tank experienced or
experiences a pH dip periodically. Your permanent inhabitants in good
health could become somewhat immune to the effects, much more so than new
arrivals. The 2nd possibility is that the fish you purchased all came
from a significantly different pH than what you currently have. Measure
your LFS's pH.

h) gH, again, looking at differentials. Either the new arrivals came
from a much higher or lower concentration of hardness, TDS or DOCs. Here
I am assuming the LFS's water was much worst than yours. Measure your
LFS's gH and make enquiries about their water changing and gravel
vaccuming routines.

i) nitrate (NO3) shock, keeping with the possibility that the LFS's water
would be significantly different than yours.... I'm assuming that your
NO3 levels are low as your recipe (planted tank, low fish load), your
water change routine, and length of the tank's operation all suggest that
your NO3 is not significantly higher than your source water's NO3. My
uneducated & unverifiable guideline is a 40ppm differential. The average
healthy medium bodied fish will usually handle a 40ppm change in NO3
without any trouble. Smaller fish can be more delicate. My
understanding is that NO3 builds up in the fish, so if moved from a high
NO3 environment to a low NO3 environment, the resulting NO3 shock comes
from their cells madly trying to dilute the NO3 out and back into the
water. NO3 shock is not evidenced by any odd behavior until they are
much closer to death. Ironically, your water might have been too clean,
and the cause of death.

Besides measuring the LFS NO3 levels, do check your NH3/4 levels too.
Even if the levels are low, there is a big difference between a fish
being slowly exposed to an increasing amount of NH3, or being suddenly
shocked by it. Best wishes

NetMax

Thanks!
-Seweryn

Would the amount of nitrate correspond in a linear fashion to the amount of
NH4 and nitirite, since nitrate is derived from NH4/NO2?
-Seweryn


i) nitrate (NO3) shock, keeping with the possibility that the LFS's water
would be significantly different than yours....

Yes, the typical nitrogen chain in an aquarium is:
Fish food (or light+plant matter) to NH3 (or NH4 under acidic conditions)
to NO2 (or directly to plant growth) with NO2 being converted to NO3 (or
again converted to plant growth). The final leap of NO3 to nitrogen gas
does not occur in any significant quantity in a typical set-up, so NO3
accumulation is either diluted by water changes, or consumed by plant
growth if the plant conditions are up to the task.

Without plants in the formula, then the NH3/4 = NO2 = NO3 conversions
are very linear (though NH4 conversion is somewhat suppressed in acidic
conditions due to the nitrifying bacteria going dormant).

NetMax

"Seweryn" wrote in message
...
Would the amount of nitrate correspond in a linear fashion to the
amount of
NH4 and nitirite, since nitrate is derived from NH4/NO2?
-Seweryn


i) nitrate (NO3) shock, keeping with the possibility that the LFS's
water
would be significantly different than yours....

I had an idea of a possible problem. I don't mean to offend if you've
already checked this.
Since most cory species spawn when the water gets softer and COOLER , maybe
you should check your heater ?
I had a similar problem years ago. I did a water change and a few hours
later my corys spawned. By the next evening all the fish were either sick
or dead. I couldn't figure out why until I noticed the f$&#1g cat had got
behind the tank and unplugged the heater cord.

Keith J.

"Seweryn" wrote in message
...
Hello everyone!

I was wondering if anyone could give me some ideas on a problem I have. I
recently bought a pair of Apisto. cacatoides, a Borneo Sucker, and 2 Khuli
snip

Well, my heater was unplugged at the time, but I had it off due to warm
weather (Had to have a fan over the surface to cool it enough)

- Seweryn

"KEITH JENNINGS" wrote in message
...
I had an idea of a possible problem. I don't mean to offend if you've
already checked this.
Since most cory species spawn when the water gets softer and COOLER ,
maybe
you should check your heater ?
I had a similar problem years ago. I did a water change and a few hours
later my corys spawned. By the next evening all the fish were either sick
or dead. I couldn't figure out why until I noticed the f$&#1g cat had got
behind the tank and unplugged the heater cord.

Keith J.