Replacing zooxanthellae in bleached zoas

[Danmuges]

I recently bleached my zoas due to a water change that may have been too warm. What is the best way to replenish (for lack of a better word) zooxanthellae in the zoas to bring back the color or is it just a waiting game. I've started dosing ab+

 

[KonradTO]

If anyone ever finds a way to actively recolonise the coral with the symbiont I am sure they would not write the details here before publishing on Nature xD
Jokes asides, as far as I know, zooxanthellae can re-colonise the coral tissue (and also a novel "group" can take the place of the former "group", more fit for the new conditions).
If you keep the zoa at suitable light conditions it should grow back to normal color