Rainbow BTA colour change?

[stuart forrester]

Has anyone had any experience with RBTA changing colour? They all start off the traditional dark reddish-orange as per the first photo when I introduce them to the tank. Then over the course of a couple of months they change to an almost neon orange - see subsequent photos. I don’t mind the colour change, they appear to be healthy and I target feed once a week. They’re under a Radion G6 Pro modified AB+ schedule with 90% peak intensity. The tank is an anemome-only set up with no corals. I carry out weekly 10% water changes and tank parameters are as follows: Alk 8.2, Calc 430, Magn 1380, nitrates 5, Phosphates 0.02, salinity 35. Should I be worried or is this just something they will do in response to tank parameters?

 

[stewy14]

it seems to me that cuz its bubbling, its stretching out the skin or flesh, and the colors are becoming more
stretched(?)

 

[OrionN]

Perhaps it needs more nutrient in the water. The zooxanthellae population is more concentrate if there is more nutrient in the water.

 

[stuart forrester]

it seems to me that cuz its bubbling, its stretching out the skin or flesh, and the colors are becoming more
stretched(?)

The bubbles are quite pronounced on the more established nems, it did cross my mind that might be contributing to the paler more translucent colours I’m starting to see.

 

[stuart forrester]

Perhaps it needs more nutrient in the water. The zooxanthellae population is more concentrate if there is more nutrient in the water.

My phosphate is quite low, I run quite a large refugium and periodically have to dose phosphate to get it into a detectable range