Are lemon tetras sensitive to something?

[LaurieinIA]

I added 4 lemon tetras to my planted, tetra community on Monday evening, along with 4 Columbian blue tetras.  Of the lemon tetras, I found 2 dead this AM and another just now. All other fish seem fine. 

40 gal planted with Val, dwarf sag, a red tiger lily, and some ludwigia ovalis. 

Parameters just now: ammonia 0, nitrites 0, nitrates 5 (all using API liquid tests) temp 74.  hard water... GH and KH are both high, pH 7.6 I think... not sure of exact readings because  I have a hard time reading test strips

stock: 10 ember tetras, 14 VonRio tetras, 4 Columbian blue tetras, and now just 1 lemon tetra. 

Everything I’ve read indicates they should work in my setup. What did I miss?  Or is it just bad luck with this batch?
 

Edited May 5, 2021 by LaurieinIA
Clarification

[Trish]

This is a quote from another site... "The Colombian Tetra is very hardy and is a good beginner fish, however it is fairly aggressive and should only be kept with more nippy, active and aggressive tetras, such as the Serpae, Blind Cave,Buenos Aires and the Silver Tip Tetra. Colombian Tetras are definitely not good companions for smaller tetras."

My lemons in a the 40 gallon have always been gentle and don't tend to bother others, so I'm thinking they might be getting picked on?  I don't think I'd keep Embers with Columbian Tetras. 

 

Edited May 5, 2021 by Trish

[LaurieinIA]

@Trish thanks for the info on the embers. So far, so good, but I’ll keep an eye on them. They weren’t in my original plan for this community, but got moved in because they were suddenly tearing my betta’s fins up... I would catch them in the act.

[Trish]

I have always strived to keep stress down amongst community fish.  The Columbian is a more  aggressive variety of tetra and it is recommended they are kept with like wise temperament fish.  Lemons tend to get a little aggressive with themselves only at breeding time, chasing each around  otherwise they are peaceful.   I would always be wondering about the columbians.  Myself I still wouldn't keep Embers with them.

https://tetra-fish-care.com/colombian-tetra-tank-mates/

[LaurieinIA]

@Trish I understand what you’re saying. 

However, right now it’s a decision of 10 embers_obviously_picking on one betta... or 4 Columbians_potentially_picking on 10 embers.

I feel this is the better option right now as the embers have more hiding spots away from the Columbians than the betta has from the embers in that tank.  

[Ken]

3 hours ago, LaurieinIA said:

I added 4 lemon tetras to my planted, tetra community on Monday evening, along with 4 Columbian blue tetras.  Of the lemon tetras, I found 2 dead this AM and another just now. All other fish seem fine. 

40 gal planted with Val, dwarf sag, a red tiger lily, and some ludwigia ovalis. 

Parameters just now: ammonia 0, nitrites 0, nitrates 5 (all using API liquid tests) temp 74.  hard water... GH and KH are both high, pH 7.6 I think... not sure of exact readings because  I have a hard time reading test strips

stock: 10 ember tetras, 14 VonRio tetras, 4 Columbian blue tetras, and now just 1 lemon tetra. 

Everything I’ve read indicates they should work in my setup. What did I miss?  Or is it just bad luck with this batch?
 

My Lemon Tetras have been bomb proof. Everybody made through quarantine and moving to the display tank. I suspect you got some that weren't well. I'd try again from a different source if you like them. Now that mine are a little older they really do look good.