Hi and welcome to AA
Your
LR and Live Sand will be sufficient to cycle the cube, you will want to do maybe 20% water changes weekly or so during cycling to keep nitrates/nitrites/ammonia at a reasonable level.
Keep those levels monitored and after a few weeks or a month or so it should level out.
4 damsels in a 12gal along with
LR and
LS is what made the spike go up so high I would think. You really do not need so much livestock to get that puppy cycled.