Purple Bonsai browning out a bit..thoughts?

[LoJack]

Yeah its the phosphates. I've found with my SPS, the purple corals are your indicators for your phosphates. That, and diatoms on monti cap rims … those two things always trigger me to test if I see them.

The worst part about the bonsai, it takes a day to fade to brown … it takes a month of perfect water to bring it back, if you're lucky.

FWIW the coral in the photo doesn't appear to be a purple bonsai. It's definitely from the valida family, which is where the bonsai is too, but doesn't appear to have the polyp shape that the purple bonsai usually has. I could definitely just be plain wrong, but something looks off. Its a gorgeous piece though, much nicer than my purple bonsai frag thats only grown about an inch over an entire year lol.