Hey there!!
I would think that because the snail died and your tank hasn't cycled is why you had the higher ammonia which is why I was curious before if you dropped in a piece of raw shrimp. It wouldn't effect it if the tank was cycled. Do you have a filter on that powerhead now? I guess they also make screens for them so fish don't get sucked and stuck.
I hope you are still feeding the tank daily. I know even though you have no fish in there the bacteria needs it.
I don't know how to raise the alk as I never tested my tank personally and don't add any of those chems to raise it. I did have the reef store test it once this year and they said it was great and asked what I used!! LOL
Again I don't remember how I cycled my tank 20 years ago. So I don't know when you are supposed to do a mini water change.
I searched and found this under new hobbyists:
Now . . . add a RAW, peeled shrimp. Drop it in the tank and let it sit there. As the shrimp decomposes it will add ammonia to the system to jump start the nitrogen cycle. You could accomplish the same goal by feeding the tank as if there were fish in it, you would also accomplish the same goal by adding some hardy fish but you take a gamble with that approach. You stress the fish which can lead to ICH, possibly kill them, wasting money. Why bother with that when a raw shrimp will work just as well.
At this point its time to sit and wait. Your tank will go through a process of establishing bacteria cultures that are capable of processing fish waste. First your ammonia will spike and then fall, then the nitrites will spike and then fall. Both ammonia and nitrites are toxic at any level to marine animals. They both must be zero.
After nitrites have fallen to zero, nitrates will begin to rise. At this point the cycle is complete and algae will begin to grow. It is now time to add a clean up crew and do a water change. (which will be covered in detail at a later date).
I don't think I would add any chems to it until the cycle has been completed. Patience!
I like your avatar!! Beautiful!