Amano shrimp death

Hi! I got 10 Amano shrimp from my LFS and one of them died in about 20 hours since I got them. I am unable to figure out why. My LFS store owner said it is definitely my fault. I need help in understanding why it happened.

I have a tank of 18" x 12" x 12" (45 cm x 30 cm x 30 cm).
Oct 2019: I set up a lazy dry start in my tank with a big bowl of Amazonia soil and Montecarlo. I later added some mature Crypts from another tank.
Jan 2020: I filled the tank with water from my existing mature aquarium and set up an HOB filter. I occasionally added some fish food to cycle the tank.
End Feb 2020: I started leaving the lights on for 6 hours (earlier it was 5) splitting it into phases of 3 hours each to allow some algae to develop.
Mar 2020: I added 10 Amano shrimp to the tank. Parameters were Ammonia 0, Nitrite 0, Nitrate <5, GH 4, KH 2. 20 hours later one dies. Temperature ranges from early twenties (Centigrade) at night to late twenties in the afternoon. pH is 7. All the other shrimp were healthy and cleaned off the algae in the tank. I transferred them to my bigger tank to keep them safe for now. I saw the dying shrimp in its last moments. It had a pink spot on its neck and was struggling to move. After a while it went upside down and its struggle slowly reduced. It was painful to watch.

I got a total of 6 Otocinclus and 10 Amanos from my LFS. The Otos went to the mature tank. One Oto died within a few hours. The LFS guy said he would replace it for free as he had lost some fish the last few days.

Any thoughts on why the shrimp may have died? Thanks a lot in advance for sharing your thoughts and experiences.

 

That pink stripe is often call the "White stripe of death" and for good reason.
It means that your shrimp tried to molt but failed. Often shrimp will molt after being introduced to a new tank. Something went wrong with this one.

I'm not sure about the oto though.
Edit: richie.p what do you think?

 

That pink stripe is often call the "White stripe of death" and for good reason.
It means that your shrimp tried to molt but failed. Often shrimp will molt after being introduced to a new tank. Something went wrong with this one.

I'm not sure about the oto though.
Edit: richie.p what do you think?

Thanks a lot.

Yes, maybe it went through an unsuccessful molt. It did look like it was struggling with some health issues though - it was struggling to move and eventually went upside down. I am no expert, so I cannot say for sure what the problem was.

As for the Oto, the LFS guy thinks it was because of his water conditions. It looked quite sick even before I put him into the tank. He feels the Amano died because the bacteria in my new tank did not colonize properly despite 5 months of cycling.

 

GH looks a little low which can affect moulting - would have thought that would be longer term though. LFS saying your bacteria/cycle are off looks nonsense if your ammonia and nitrite are still zero. How did you introduce the shrimp in the first place?

 

GH looks a little low which can affect moulting - would have thought that would be longer term though. LFS saying your bacteria/cycle are off looks nonsense if your ammonia and nitrite are still zero. How did you introduce the shrimp in the first place?

Thanks for your note.
I drip acclimatized the shrimp for a couple of hours before adding them to the tank. The shrimp died about 20 hours after it got added to the tank.
The reason the LFS guy is convinced that it is a bacteria issue is because the water looked a little cloudy due to the high algae content.

I suspect that the water which the LFS has recently been using may have contributed to the problem. He did inform me that he lost some fish in the past few days, because of which he is ready to replace the lost Oto.

I also wonder if the temperature here may have affected the shrimp. It was about 35 degrees Celsius outdoors, and it took me about 30 minutes to transport them on my bike.

 

that is warm! Dunno the affect of a temp spike on Amanos. As Canaculus says change in water can trigger the moult (even just the weekly water change) but looks like something else caused it to fail.
The tank is 10 USg - 10 Amanos is a lot to start with. I've not seen anywhere else other than here (I've done a lot of research) that recommends more than one per two gallons. I would always recommend starting with that and, if things work out, maybe build up from there a few at a time. Again though not saying that's the cause of your dead shrimp just some extra advice - hopefully you'll be ok with the rest of your shrimp.

 

Thanks a lot!
Maybe the cause of the poor Amano's death will remain a mystery.
Hopefully the rest of the shrimp will do well - yes.

I had intended to breed the Amanos - that is why 10 in the tank. After a couple of weeks, I will move the Amanos slowly back into this tank. They seem to be enjoying themselves in the main tank I have.
And yes, I am aware of the Amanos' breeding process. At least theoretically. Have taken it up as a challenge.