Your nem is clearly unhappy.
Could relate to the big waterchanges and therefore changing waterchemistry to quick.
Stability is the key. Get your water parameters stable, don't chase certain numbers.
Get your own testkit(redsea,salifert,hanna).If you can't afford it you shouldn't be in the hobby. I don't know what a spin test is.
If you make your own water use rodi water not straight from the tap, same for top up water.
Get a clean up crew going to combat the hairalgae,if you can get a piece of live rock to seed your tank with coralline algae, where coralline grows no other algae grows.
Hope your nem makes it.