Zapins· Plant Whisperer
Not sure if you meant this post for me or for OVT, if it was for me, I don't mind. I'm not always correct about every problem. I like to work my way through the list of likely problems then move on to less likely problems.I don't know, I have had a few and many have done this, just to grow back perfectly. I don't want to say you are wrong, and you are my plant mentor, but I have never not had this plant suffer unless, something else is suffering.
The OP posted a picture of his A. reineckii on APC which also has holes. The OP didn't post that photo here so I suppose I have an unfair advantage coming to this thread.
Most of the holes look a lot like nerite holes since they are fairly irregular and seem to lack the boarder that potassium deficiency has. However, not all the holes look like nerite damage and nerites will often eat weakened plants, or eat dying patches of plant tissue. So perhaps the nerite simply ate through the leaf where the potassium deficiency symptoms are. Either way two plants in the tank with potassium-like holes seems to suggest a possible lack of potassium, which is easy to test and rule out.