10 Gallon Tank What in water would kill Betta but not shrimp?

Folks looking for some help here. I set up a 10 gallon aquarium for a Betta fish in my upstairs office. It has two java fern, anubias and red root floaters. I used filter material from my main tank which is cycled.
ammonia -0
Nitrite - 0
Nitrates 5
Ph - 7
Temp - 25.5
I got my Betta and three amano shrimp and they were all great. I then did a 25% water change after 1 week and used prime. I used my bathroom taps. The Betta started to show signs of distress and was gasping after 24 hours. I tested the water and all levels were 0 after the water change. I felt it was the upstairs water and did a further water change using the downstairs water taps which I use for my main tank.
The Betta sadly died after 48 hours. Approx 1 week after getting him. All three shrimp are fine, eating, moulting and no issues.
The Betta showed now signs of fungal, bacterial or parasites.
I honestly think it was my upstairs water but I can’t think what is in the water that would kill a fish but not shrimp.
Any ideas are welcome? This is the first fish I have ever lost and I am very upset by it especially if it was a mistake I made.
Photo of Alaska the day before.

 

Why would the water be different from different taps?

 

The hot water all comes from the same tank but the downstairs water is mains fed whereas the bathroom cold comes from a tank in the roof space.

 

Do you have an airstone or something causing surface agitation?

 

Yes have an air stone and an internal filter
Of course I may be barking up the wrong tree completely but the different water sources is the only obvious difference between the two tanks.

 

Honestly, in my opinion, the most likely cause is that you purchased a sick Betta. Internal parasites are quite common and can be very hard to spot.

In the photo you showed of Alaska did he just eat?

Whatever the case, I am so sorry for your loss. I've been running a small Betta rescue for 7 years and have lost so many pets that I've ultimately decided to quit (maybe temporarily, maybe permanently). I know rescuing is supposed to make you feel joyful that you saved a life and gave someone in need another chance, but it was ultimately bringing down my naturally cheerful demeanor and making everyday life hard. I couldn't focus, forgot all of my schedules, even stopped feeding the fish for a week when one of them passed. Losing a beloved fish is really hard, sadly not a lot of people understand the feeling.

 

Honestly, in my opinion, the most likely cause is that you purchased a sick Betta. Internal parasites are quite common and can be very hard to spot.

In the photo you showed of Alaska did he just eat?

Whatever the case, I am so sorry for your loss. I've been running a small Betta rescue for 7 years and have lost so many pets that I've ultimately decided to quit (maybe temporarily, maybe permanently). I know rescuing is supposed to make you feel joyful that you saved a life and gave someone in need another chance, but it was ultimately bringing down my naturally cheerful demeanor and making everyday life hard. I couldn't focus, forgot all of my schedules, even stopped feeding the fish for a week when one of them passed. Losing a beloved fish is really hard, sadly not a lot of people understand the feeling.

Thank you for you kind words.
No he hadn’t just ate in the photo. Well, he had had some hikari Betta pellets for his breakfast at 8am and the photo was 13.30. I don’t routinely treat for internal parasites.

 

I agree with the writer above, I think you got a sick betta.

 

Thank you for you kind words.
No he hadn’t just ate in the photo. Well, he had had some hikari Betta pellets for his breakfast at 8am and the photo was 13.30. I don’t routinely treat for internal parasites.

Ah, I see. Sadly, the post makes me believe he likely had internal parasites. They can be very difficult to notice and treat, which is why I always try and soak pellets in garlic at least twice a week. This would explain why the Betta didn't make it but the Shrimp look and are acting perfectly fine.

 

Thanks as long as I know for the future. I didn’t want to jump in and get another Betta without knowing where I went wrong.

 

You might hold off on getting another for a decently long amount of time. See what happens to the shrimp.

 

You might hold off on getting another for a decently long amount of time. See what happens to the shrimp.

Yeah I just meant further down the line.