What happen ?

[Adolfo]

My colonie was in my tank for about 6 months with no issue
week ago lost tissue in one tinny place but grow back to normal
now happens again
any clue ?
Thanks

 

[Rp8]

water parameters?

 

[Rp8]

and light source and height above water?

 

[Adolfo]

water parameters ok light source photon v2 like 12" above par around 300 ish
That one is not the only acro in my tank keep several others with no problems