Hmm, not much of a spike at all, especially with a raw shrimp in there. Was this fully cured LR
that you got at a LFS
and put straight into the tank?
What test kits are you using?
It usuallly takes about a week for the shrimp to decay enough to cause a big spike, then another 3 weeks or longer for the cycle to complete. With enouhg fully cured LR
it could happen this fast (maybe). In that case I would pull the shrimp out, let the cycle complete, then do a 30% or larger PWC
. Wait another week, test, and if everything still looks good you can start adding livestock (slowly).