You don't need the algaecide. Whether to use the dichlor for a little while or the bleach instead is up to you. I am more familiar with using bleach and just adding CYA separately because that is what I do in my pool. But, in these little pools (or any new pool for that matter) using dichlor is a good way to add both at the same time. Either way is just fine. Since you already have the dichlor, maybe just go ahead and use it for a bit but just watch your CYA level and when it gets to around 40-50, switch to just plain bleach.