Probably ich but just making sure

[SWilson]

Yesterday I got a tiny blue eyed lemon BN Pleco. They’re currently the only fish occupant in a 20g long with many mystery snails and cherry shrimp (which I got from the same place). (Picked up from a wholesaler in lieu of shipping so did not get to inspect/pick them out before purchasing)
Upon closer inspection of my new friends this morning, I’m fairly certain the pleco has ich, and so I started the first dose of ich-x this morning. 
but what gives me pause is that the spots don’t seem uniform, which I thought ich was supposed to be. 
The pleco is more ivory than lemony so the spots are very hard to see, definitely on the fins which points towards ich. I think I can see them on the body, and they appear to be raised. 
 

I was hoping to get a second opinion here on whether it is indeed ich or something else. 

I remember watching or reading an AC blog post or video that talked about diagnosing ich vs other diseases that may look similar—is anyone else familiar with that? 
 

related question, I know ich-x itself is shrimp safe, but does anyone have experience with how following the course of frequent, 30% water changes might impact the shrimp? I know they don’t like large water changes at all. 
 

tank is unheated (low 70s temp), 0 ppm ammonia/ nitrite/ nitrate (it is cycled it was just running with plants a few snails only for a while and before I got the new inhabitants I did a 100% water change with heavy gravel vac’ing. Ph around 7, 300 gh, 40 kh (too low - I’m running out for more crushed coral later today). 
 

Thanks in advance!

[Keeg]

Shrimp will not get ich from a fish, it is extremely extremely rare for parasites of any kind to transfer from fish to invertebrates. If you're concerned about the shrimp, you could always remove the pleco into a hospital tank and wait out the parasites in the main tank while you treat the pleco. Which is what I would do. Ich can live a lot longer than other parasites, around 70ish days I believe without a host. 

While I'm fairly certain that is ich, ich-x targets more than just ich, so I doubt you'd have any problems.