Then, last night I was exploring some info about guineas on the PETA website (they don't have a very comprehensive info section, but just the basics) and it mentioned something about salt blocks. This intrigued me, since I have read just about every single website and book about guinea pigs, and never heard anything about salt blocks.
It makes some sense that they need more salt, since it doesn't seem like they get much in their diets. Guinness has also been drinking water like crazy lately, so I was thinking maybe he needs more salt to retain water.
Today I read some things on guinea pig discussion website, and people said salt blocks are unnecessary. One person even said it can hurt them by causing kidney/bladder stones. I'm not really sure what to think!
Oh well, if anyone has any info about these salt blocks, let me know. I will probably buy some and see how Guinness likes them. If it looks like he's eating too much of it, I'll take it away. I'll update soon!