Intriguing Pulsing Xenia

The Pulsing Xenia (Heteroxenia sp.) is a mystery in the captive reef community.
I had a previous experience just like many others have had:
Got a small Xenia, watch it grow, watch it spread like weed, and then they all disappear within weeks for no apparent reason.
I was visiting a friend and he was selling some of these small pulsing frags (the ones he had was very very energetic and robust, sometimes you do encounters "lethargic" xenia). I wasn't planning on getting them but my wife was very intrigued and find them amazing to watch so I got a small colony.(below)

pulsing xenia

I am honestly not expecting much out of this thing since I had a previous experience similar to many. It's been about a month now and there seems to be no sign of slowing down in these critters' pulsing and also no shrinking of their polyp extension.

The common opinion about keeping them healthy is:

Light: Strong to medium light (T5 or PC is good enough, you might want to move them to the side and bottom if you are using MH like me)

Flow: Medium. Your current need to be strong enough to bring water and food to it, but not too strong to cause any flesh damage.

Water Quality: From my understanding, not too clean. As a matter of fact, the pulsing movement can logically be their act of "capturing" planktonic food from the water current (though not scientifically proven), but it seems that everyone who keeps their water "too clean" has problem encouraging growth and proper polyp extension.

Lastly, as you can find online, I too have read mixed opinion on the maintenance of this unique creature and have personally experienced various results in various conditions. Fortunately they are not too expensive to come by and are mostly aquacultured. You will definitely have better luck in hardier specimen home cultured and also save some $$.

Lastly, due to the speed they can grow and spread and the level of ease to care for, I honestly don't think anyone should pay more than $15 for a colony of the size shown in the photo above, if you are paying more than that, you are being overcharged.