Possible causes for shrimp wipeout??

[chongj88]

Hmmm, where do I start? Oh well, the short story here is that in the space of 5 days, my entire shrimp population (8 Yamatos, 40+ bee shrimps) was wiped out. Needless to say, I am both frustrated and curious.

All I can say is that before I left for my 5 day vacation, everything has been dandy for the last 6 months. The only exception was that I just started dosing my water column with Seachem FE just before I left.

So, does anyone here have any similar experiences with dosing FE in their water column? What else could have caused this wipeout? By the way, all my cardinals and otos seem to be unaffected.

Thanks for sharing my frustrations. []

[David]

hiya chongj88

on a guess basis, what is your tank size and how many fish have you got. When you are away on vaction for 5 days....did you do a fresh water change prior to leaving or not? if not when was the last change. Did you use an autofeeder or did you get someone to feed your fish, or left it unfeed?

shrimps are very sensitive to sightly higher levels of NO2 or NO3 while fish are uneffected. It could also be the water temperature as all ventilation is closed while you are on holidays.

it may not be the FE thingy you put, but i will not rule it out.

[chongj88]

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On 12/23/2002 12:21:47 PM

on a guess basis, what is your tank size and how many fish have you got. When you are away on vaction for 5 days....did you do a fresh water change prior to leaving or not? if not when was the last change. Did you use an autofeeder or did you get someone to feed your fish, or left it unfeed?
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Hi David,

Thanks for taking your time to respond. You have raised some pretty good questions which got me thinking... First off, my tank is 3ft x 1.5 x 1.5. 40+ cardinals, 5 otos and (previously) 8 yamatos and 40+ bee shrimps. I did perform a partial (30%) water change before I left. At the same time, I did introduce a feeder of which I actually increased the feeding frequency from my usual.

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shrimps are very sensitive to sightly higher levels of NO2 or NO3 while fish are uneffected. It could also be the water temperature as all ventilation is closed while you are on holidays.

it may not be the FE thingy you put, but i will not rule it out.
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Good point about the NO2/NO3 levels... While I have increased the feeding frequency from once to twice a day, I am a little skeptical that the NO2/NO3 level could have shot up so high in 5 days... There was once when I came back from a long vacation (3 weeks!) and only 2 of my yamatos died... NO3 measured above 100ppm then... While I did not measure it this time, I am quite sure that it should not be so high after just 5 days. Furthermore, my tank is matured now as compared to when I took my last 3 week vacation. By the way, I have those Ocean Free fans blowing 24 hours a day. Even with ventilation down, I doubt temperature could have risen about 30deg.

Anyway, thanks for the pointers. I am going to experiment again by putting in Malayan shrimps this time (cheaper [] ). We'll see what happens next.

John

[DEA]

*peep*

i don't know why people keep on thinking that it takes a while for no2 to increase
after all, that's the main cause of New Tank Syndrome

i'd go with the nitrite idea

[David]

hi chongj88

no problem..coz long trip vacation disaster a plenty i have been through[]....NO3 going up in a few days is very possible as increased frequency of feed done through auto feeder increases the bio-load that may throw the tank into a new cycle....one of my experences is that the auto-feeder's drop amount is not constant and what was apportioned before actually doubles..this happened to me before. After a 7 day trip, when i got back the feeder had no balance of food much to my suprise...on testing, the feeder due to the food powder particles actually case the motor to jam slight and the turning cycle was prolonged, dropping more than what was required.

my last trip last year for 5 days.....this time, no auto feeder and i got my family to come by my place every 2 days to feed. Before leaving I did a 40% water change. When i got back, my yamatoes got wiped out and NO2 and NO3 levels were in nightmare levels....

I could figure it out till yimin pointed out that my ehiem rock thingy was due for change as I have not done so for 2years.....after changing, everything was fine after about 2weeks or so.....

just to share with you[]

[chongj88]

Hmmm, interesting... I never thought by increasing feeding frequency will throw the tank into a new cycle. Well, at least it is a lesson learnt for me. Always good to hear from the more experienced folks here.

Now that I am back, I have taken off the feeder and am resuming the once a day feeding frequency. Also just ordered 100 malayan shrimps from Ben today ($8 only). Will see what happens next.

Oh yeah, I also better remember to check NO2 levels more frequently now. Somehow I always assumed that a matured tank will not have NO2... Guess I am wrong.

[David]

hi chongj88

just sharing experiences[] wish i dont have to go through the pain of expensive lessons[]....

[DEA]

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On 12/24/2002 12:01:08 PM

Hmmm, interesting... I never thought by increasing feeding frequency will throw the tank into a new cycle.

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the 'cycle' is dynamic
once your water parameters change, the biological cycle can and most often will change along with them
you increase fish load? more N, you get spikes
less fish load, less N, the bacteria starve and die off, small spikes
get what i mean?