# Massive Shrimp Deaths



## imatrout (May 12, 2005)

I have had a massive die off of my Amano and Cherry shrimp in a tank that has been up and running perfectly for nearly 2 years. This is the second die off in a week. The first I attributed to a CO2 overdose when my surface skimmer clogged. I add a lot of CO2, but have always done so. Originally I thought the surface scum pushed the CO2 over the edge by inhibiting the oxygen transfer at the surface, but this latest die off came with the surface completely clear. The fish and plants are fine and active, no gasping at the surface etc. My parameters are PH 6.6, KH 4, Nitrate 20 PPM.

Any ideas what might be causing this? I have done nothing different with ferts or new fish or plants.


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## milalic (Aug 26, 2005)

Maybe you have some spike in ammonia. Hard to tell, but shrimp are more sensitive than fish. Something in the water is definitively killing them. Have you feed them food containing copper?

-Pedro


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## gibmaker (Jan 3, 2007)

*shrimp*

the only thing I know that will kill shrimp that fast is a algae cure or something of that nature, although you did say that you have done nothing different


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## toddnbecka (Sep 20, 2006)

The continued deaths may be the long-term result of the original problem. Nitrates @ 20 ppm is a bit high for shrimp, possibly a borderline situation regarding water conditions that crashed when something else went wrong.


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## Ankit (Dec 9, 2006)

Agreed, that nitrate level is a bit high - plants like frogbit will help to lower those a lot.


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## imatrout (May 12, 2005)

Woke up this morning and foud ALL my fish sucking at the surface like they were oxygen starved. I don't get it though as the CO2 has been off all night and this time there was no surface scum to limit the oxygen exchange. Is there anything else that can be causing these type symptoms or any other wzy oxygen can be depleated in the water?


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## gibmaker (Jan 3, 2007)

imatrout said:


> Woke up this morning and foud ALL my fish sucking at the surface like they were oxygen starved. I don't get it though as the CO2 has been off all night and this time there was no surface scum to limit the oxygen exchange. Is there anything else that can be causing these type symptoms or any other wzy oxygen can be depleated in the water?


Depending on how much co2 you are dosing during the day it may affect the overall amount in the evening, if your lights are not on then the co2 is not being readily taken in by the plants, maybe the concentration does not drop in the evening????? I read somewhere that you should add a lot of oxygen in the evening or when your lights are out to get rid of some of the co2 in your tank that is not being absorbed by the plants????? just a theory, then again I might just be full of crap


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## milalic (Aug 26, 2005)

imatrout said:


> Woke up this morning and foud ALL my fish sucking at the surface like they were oxygen starved. I don't get it though as the CO2 has been off all night and this time there was no surface scum to limit the oxygen exchange. Is there anything else that can be causing these type symptoms or any other wzy oxygen can be depleated in the water?


What is the temp in your tank?

-Pedro


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## imatrout (May 12, 2005)

Temp is 83.5


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## imatrout (May 12, 2005)

gibmaker said:


> Depending on how much co2 you are dosing during the day it may affect the overall amount in the evening, if your lights are not on then the co2 is not being readily taken in by the plants, maybe the concentration does not drop in the evening????? I read somewhere that you should add a lot of oxygen in the evening or when your lights are out to get rid of some of the co2 in your tank that is not being absorbed by the plants????? just a theory, then again I might just be full of crap


You are absolutely correct and NOT full of C___. Thing is, I usually have gotten by with pointing a return nozzel at the surface to break the surface tension thereby oxygenating the water. It's never been a problem for nearly 2 years. Otherwise the plants and fish (discus) are happy and healthy


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## milalic (Aug 26, 2005)

imatrout said:


> Temp is 83.5


At high temps their is O2 starvation in water. You need more sources of O2 in that tank. I had this problem in a shrimp tank. I increased aeration and never had a problem again.

-Pedro


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## imatrout (May 12, 2005)

milalic said:


> At high temps their is O2 starvation in water. You need more sources of O2 in that tank. I had this problem in a shrimp tank. I increased aeration and never had a problem again.
> 
> -Pedro


You are right about the temp, but like I said before, its been set up like this for almost 2 years and never hasd the problem. That said, I am going to adjust the outflows to create more surface disturbance. That should help.


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## bluegardener (Jun 5, 2006)

Have you smelled your tank to see if there's sulfur? After 2 years maybe the gravel's compacted.


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## jeff63851 (Feb 23, 2005)

I've also had one major shrimp die off over the past week. It's usually because of a nitrate spike since I rarely clean my filter. Whenever I start seeing some dead shrimps, I would usually do a water change along with maintaining the filter. Have you checked your filter?


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## tefsom85 (Jan 27, 2007)

You mentioned that you are concerned about excess CO2. Do you have a drop checker in the tank to help determine the CO2 level? Perhaps the CO2 is too high all day long but it is somewhat offset by the plant intake. Just curious, 83F seems like a pretty high temp. Do you have a reason to keep the water that warm?


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## imatrout (May 12, 2005)

tefsom85 said:


> You mentioned that you are concerned about excess CO2. Do you have a drop checker in the tank to help determine the CO2 level? Perhaps the CO2 is too high all day long but it is somewhat offset by the plant intake. Just curious, 83F seems like a pretty high temp. Do you have a reason to keep the water that warm?


Yes, I now have a drop checker, but at the time I did not. The reason the tank is kept so warm is that I keep discus in that tank and they require warmer water. In fact, I keep the tank at the lower end of the suggested range.


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