tube coral dying- help

[Auryn]

some of you might remember- i got some awesome colonies of tube coral on a piece of lr i bought 2 weeks ago

they were doing fine

eating- i coudl see them catching live bs and taking them into their tubes

ive noticed some have begun to bleach and i can't see their tentacles anymore

only about 20% of the ones that were alive when i brought it home are still alive

all params are fine

salinity is at 1.025

ph 8.3

phosphates 0

ammonia 0

nitrates and nitrites are all in check

calcium at 400

 

my green and red hair algea has even begun to dissapear

my shrooms are doing well

the orange sponge that came on that same piece of lr is doing really well

coralline algea is doing well

my condy anemone is doing well

 

is it possible the hermit crabs are killing them?

 

anyone know what I can do to bring these guys back?

oh yeah lighting is 2W per gallon of 50/50 lighting

its a 12gl nano and these tube corals are at the most 5 inches away from the light

 

any help is greatly appreciated

i dont want to lose these guys

[Auryn]

theres even a clam in there that came in on the same piece of lr that seems to be doing fine

regularly scares the crap out of me by blowing sand out when i least expect it

i have a bijillion of pods running around

[reefsrule]

how often do you feed? I would reccomend feeding frozen mysis too. They need to eat at least every 2-3 days. One time a part of my black tubes died for no reason and the rest of them were fine. Make sure all the tubes get food individually, they are all seperate animals.