Sinking betta food! Please help?

I bought my male crowntail betta TOP FIN color enhancing bites he is doing fine on them sometimes when im not around they will sink to the bottom of the bowel and i know this causes amonia for bettas so how can i get the food out it sinks into the gravel if i buy a small filter like the TETRA WHISPER 3i in tank filter would this help? Thank you