Need help with (possibly) healthy white acropora

[douglaslps]

A quick introduction to my tank:
- 200 liters display + 50 liters sump
- 3 AI Prime (2 hours ramp up, 5.5 hours on constant light, 2 hours ramp down - 98% on blue channels + 25% on white)
- Tunze DOC Skimmer 9410 cleaned weekly
- HOG1x ATS removing algae weekly
- Dosing balling with automatic doser twice a day
- AI Nero 5 as the circulation pump

Now the problem: I recently purchased a millepora acropora frag that was showing a really soft green and yellow coloration (the seller didn't mention he was using an orange filter for the pictures).
When I received it, to my surprise I could barely see any color.
I questioned the seller and he told me that his colony is also whiteish without camera filters.
I still can see the polyps extending and no algae are growing on it which are both good signs, but I was expecting it to have some color to the bare eyes.
This is a picture of the colony the frag was extracted from:

And then some pictures of my frag (I tried to do my best to adjust the white balance):

Sorry for the poor picture quality that I took with my phone but you can see the polyps here and there...

Note: I recently bumped my potassium back to 400 and started doing monthly water changes (did the second a few weeks ago) after reading this reefbuilders guide: https://reefbuilders.com/2008/09/03/guide-of-sps-coral-coloration-make-them-more-vivid-bright/#

Ideas on how to get the mille color back?

 

[Silent]

What are your nitrates and phosphates at? What are the levels of the tank it came from? Are you both possibly running a ULNS? If the seller is than it might take months for it to color up.

 

[douglaslps]

I haven't checked my nitrates in a while. Last time I checked my phosphates (two months ago) it was showing 0 both on a Hanna reader and a Salifert test kit.
I get that as good news since the lack of color was to me, an indication that there were no zooxanthellae on the milli and that would cause it to die.

 

[JCOLE]

What spectrum are your lights running at? To me the first picture looks heavily saturated in all blues while yours has a lot more whites. Would be interested in what yours look like with all blues and a filter on your camera?

 

[Graffiti Spot]

Looks like a fresh wild Tonga Mille. If your frag is white it’s going to take time and a stable tank. That’s about it.

 

[45ZoaGarden]

I see hints of the color. Get an orange filter or orange glasses to look at it. What are n&p? 0 phosphates is not good. 0 could be 0.00 or 0.90... what about the big 3?

 

[jda]

That is a frag from a severely bleached wild colony. The best thing for it right now is just time, patience and stability.