Black widow nem shrinking?

Sstadler · Nov 7, 2020

I’ve had this black widow nem for 6 weeks or so. Tank is almost two years old. All corals are fine. All other inverts are fine, including a rainbow BTA. No fish because system is fallow. The nem in question has been slowing shrinking for the last 3 weeks. It was like twice the size it is now and it was fully extended. It has been being manually fed mysis / brine 2-3x a week. It is approximately 5 inches under the waterline underneath a kessil 360. It does not move. It’s foot is strong. Colors are still strong also. Thoughts? Flow is low/medium

Params:
1.024 sal
0 am
0 nitrite
20 nitrate
0 phos
79.0 temp
Cal 440
Mag 1440
Alk 7.7

Pillahump · Nov 7, 2020

possible chemical warfare between different kinds of nems?
do you run carbon?
either that or could be a lighting issue.
not exactly sure lets ask @OrionN

Sstadler · Nov 7, 2020

Pillahump said:
possible chemical warfare between different kinds of nems?
do you run carbon?
either that or could be a lighting issue.
not exactly sure lets ask @OrionN

I do run carbon. Just the minimum amount as recommended by BRS. I have a rainbow nem that is approximately 2.5 feet away. But the rainbow is healthy

Pillahump · Nov 7, 2020

Sstadler said:
I do run carbon. Just the minimum amount as recommended by BRS. I have a rainbow nem that is approximately 2.5 feet away. But the rainbow is healthy

from my past experience when i had two different types of BTA's the dominant one would make it and the other would slowly die off...not sure why...some say its "chemical warfare"

Lovefish77 · Dec 7, 2020

Just give it time. Your light seems to be enough, any idea on par? Maybe it is the 20 ppm nitrates if that nem came from different parameters? Never had that high nitrates with nems.

Grill · Dec 7, 2020

Pillahump said:
from my past experience when i had two different types of BTA's the dominant one would make it and the other would slowly die off...not sure why...some say its "chemical warfare"

I had this happen to me. Had a rainbow BTA for nine months with zero issues. Added a different BTA and the rainbow slowly withered away. I'm still not 100% sure what happened but like others have said could be a type of chemical warfare going on. A black widow nem is beautiful... Good luck with it.