So, you actually found a bug – thanks so much for taking the time to ask the question here!
The default recipe had muriatic acid listed as a dry chemical, not liquid – whoops! I just updated the recipe online, you’ll need to manually select the new version in the app (select pool -> select recipe name -> select “Default” from lower part of the list -> “Use Recipe”).
I’m trying to do this type of work out in the open, but it’s not really intuitive to follow along yet. Here was the spot I changed the recipe:
Anyways, thanks so much for using the apps & posting here – you rock!