Success with a Linckia is determined by keeping them 12-18 months. Please do not consider it "success" until this time.
The tank is quite small. IMO, DO NOT COUNT on the star taking to spot feeding. Some will, some won't. Ensure you provide the MINIMUM needs, which is a good amount of LR on which to feed.
Enough of these stars die in this hobby, and I believe your tank is marginal to keep one. It may work, but IMO, it is on the small side.
These are some of the most delicate animals to keep. They need a large, mature reef tank with PRISTINE water parameters. Please ensure your tank meets at least the very basic needs to keep one.