Re: [APD] Sudden death of all the healthy yamato shrimp

["Ann Viverette" <annv777 at houston_rr.com>]

First, sorry to see you lose the shrimp adn fish. The shrimp are often the 
first to go when there is a problem with oxygen and/or CO2. I do wonder 
about your water, I have had a large fish kill and lost many shrimp after 
large water changes when the local water levels were high and the well the 
community uses is deep, which means that the oxygen level in the water was 
lower than normal. Now, in the winter, rainy season, which when that occurs 
here, I keep the water level a bit low at first to increase surface 
agitation (as Liz suggested) and I keep the CO2 off for the first day after 
a water change. The wintertime water probably has higher than normal CO2 
levels at higher pressure as well as lower oxygen levels. So, increase 
surface agitation as was suggested. You might also do water changes early in 
the day, to allow the plants to add oxygen to the tank before lights-out.

If this is a problem again, you can add a capful of household H2O2 to the 
tank, if the fish suddenly act normal, then oxygen is the problem.

And, as someone already pointed out, you had too many fish in the tank. If 
we don't thin out a tank, Mother Nature often will step in and do it for us. 
In my case, I had already decided that with my tank of discus fully grown, I 
needed to find a new home for about 5 of the 18 fish. Unfortunately I waited 
too long and in a similar accident I lost 5 of the biggest discus as well as 
2 expensive wood shrimp and a bunch of Amano shrimp.

Ann V

> Message: 2
> Date: Wed, 28 Jun 2006 11:05:23 +0800
> From: "Ng Heng Ghee" <THGNg at ntu_edu.sg>
> Subject: [APD] Sudden death of all the healthy yamato shrimp
> To: <aquatic-plants at actwin_com>
>
> I have a 2ft (80Litres) planted tank that is 6 month old. An external 
> Eheim 2213 was used for filtration.
> The lighting is 2 x 36W PL tube, 6 hr of illumination each day.
>
> My stocking density was:
> - 80 Glowlight Tetra
> - 30 Yamato shrimps
>
> A few day ago I decided to redo the layout. No water change was done.
> I used back the existing plant and some from another tank.
>
> My new stocking density is:
> - 50 Yamato shrimps
> - 10 Malayan shrimps
> - 15 Cardinal tetra
> - 10 Harlequin tetra
> - 5 Rummy nose tetra
>
> After some feeding, I switched off the light at around midnight. Both 
> shrimps and fishes look fine and active.
> No distress was observed.
>
> But the next morning at 7am, I found some fishes and all the Yamato dead.
> The fish are breathing frantically at the waterline.
>
> The water test shows:
> pH: 7.3
> kH: Not tested (there are 2 handful of coral chip in the filter)
> GH: Not tested
> NO2: 0.3 ppm (due to the decay of the shrimp)
> NH3/NH4: 0 ppm
> Cu: 0 ppm
> Cl: 0 ppm
>
> After that I did a 50% water change and added AMMO-LOCK for water 
> treatment.
> I left the light on for 8 hr before going to work. When I reached home, 
> the fishes were still showing sign of distress.
> They were breathing at the waterline.
>
> So I connect an airline with an airstone to provide more oxygen to the 
> fish.
> It works.
>
> Could it be an Ammonia or Nitrate spike ? I used fertilizer like KH2PO4, 
> K2SO4 and KNO3 without ill-effect.
> Could I have caused a re-cycling of the beneficial bacterial ?
> Why is the fish breathing so frantically ? What cause the suddenly 
> depletion of oxygen in the water ?
> What killed the shrimps ?
>
> ------------------------------
>
> Message: 3
> Date: Tue, 27 Jun 2006 21:28:34 -0700
> From: "Liz Wilhite" <satirica at gmail_com>
> Subject: Re: [APD] Sudden death of all the healthy yamato shrimp
> To: "aquatic plants digest" <aquatic-plants at actwin_com>
>
> On 6/27/06, Ng Heng Ghee <THGNg at ntu_edu.sg> wrote:
>>
>>
>> My new stocking density is:
>> - 50 Yamato shrimps
>> - 10 Malayan shrimps
>> - 15 Cardinal tetra
>> - 10 Harlequin tetra
>> - 5 Rummy nose tetra
>
>
> That's a lot of livestock for a 80L.  I have a 70L with 9 neons, 3 yamatos
> and a full tank of plants.
>
> After some feeding, I switched off the light at around midnight. Both
>> shrimps and fishes look fine and active.
>> No distress was observed.
>
>
> It is likely that your oxygen level was pretty low at that point --
> especially if the plants were not in place for a full light cycle -- and
> bottomed out during the dark period due to the plants taking up oxygen 
> along
> with the fish.  Your test results and solving the problem with surface
> agitation all point to oxygen deprivation being the problem.  I have had 
> an
> oxygen problem in the past, and I solved it by using a spray bar from a
> cannister filter return line that points up towards the surface.  There is
> enough current flow at the surface to continually expose fresh water to 
> the
> air without so much that I see CO2 being released from the water.  If you
> are not adding CO2 then you don't need to worry about too much
> surface agitation.
>
> I suggest that you increase the surface agitation via a spray bar or a
> powerhead as both will be more efficient than an air stone and the expense
> is low.  You will also increase the oxygen content of the water if you 
> leave
> the lights on longer -- I do a 10 hour cycle on 2 tanks and a 12 hour 
> cycle
> on a 3rd tank.
>
> Sorry you experienced such a heavy loss of livestock.
>
> -- 
> Liz
> http://pottedliz.home.comcast.net
>
>
> ------------------------------
>
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>
> End of Aquatic-Plants Digest, Vol 34, Issue 30
> ********************************************** 

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