Replacing carbon or alk swing leading to closing polyps on stylopora and birdnest colony?

[educatedreefer]

Recently upgraded my 120g to 250g and had to move a few large colonies of stylopora, birdsnest, montipora, staghorn, slimer, tenius etc into the new tank and noticed an increase in alk from 8dkh to 10dkh.
i used about 20% of the water from my old tank + all my sand and rockscape and filter to maintain the existing bacterial culture, and the remaining water was from a freshly mixed batch.
the next morning, I noticed all my birdsnest, stylo, and birdsnest colonies not having full PE while all my other corals (tenuis, slimmer, staghorn, milliepora, etc) all have full PE. my flow is directed towards the stylo, birdsnest, and pocci and getting the same PAR (200-300 PAR) in the upper half of the tank, flow is 25X tank, and my nitrates are back down to 5 when i usually keep it at 20-25. i was worried the tank transition may have stressed my soft corals and caused release of toxins so i also switched the carbon bags today.
now they’re still not showing full PE and I can’t determine whether it’s the alkalinity at 10, low nitrate swing from 25 to 5 or maybe needing more flow in the tank (25x back to 50x).
Should I wait to lower alk, increase flow, or dose nitrates?
Old tank parameters:
1.026
alk: 8.4
calcium: 430
magnesium: 1550
dosing aminos daily with rotifers and mysis shrimp twice daily
nitrates: 20-25
phosphates: 0.05

new tank parameters:
1.026
Alk: 10.2
Calcium: 410
Magnesium: 1440
nitrates: 5
Phosphates 0.01

 

[Lavey29]

I've heard that colonies are more difficult to acclimate then frags in a new environment. Even though you used a lot from the smaller tank the new tank has underlying environment differences so it may take awhile for your SPS colonies to adjust. Some may go quicker then others. Some may not acclimate at all.

 

[mdb_talon]

My guess is also they need time to acclimate. The water, light, and flow are all going to be different than what they are used to.

 

[educatedreefer]

My guess is also they need time to acclimate. The water, light, and flow are all going to be different than what they are used to.

I’m hoping it just needs time to adjust, but what would you recommend I do in the event they don’t bounce back?
Funny thing, I created a few accidental frags that are perfectly happy so maybe it’s telling me it wants to be fragged and restarted? hahahah

not really sure why frags do better than colonies, but I do know their growth is incomparable once fragged.