One question if you don't mind, is there anything other than rocks I can tie Riccia to? Or could I just leave it on the mat and let it the dwarf hair grass grow into the mat? https://www.azgardens.com/p-2190-riccia-on-mat.aspx
Thanks. I am starting my first low tech planted tank!
You can tie Riccia to anything with a surface! Bear in mind that Riccia ends up adopting the shape of the object it's tied too - so if tied to say, moon stones it will have a roundish mound appearance vs. an even hedge from Riccia stones / flat stones.
I would not leave the plants on the mats they sell them on - typically they're made of some kind of fibrous material that seems to cause more issues than it solves. If it is on a steel mesh, it would be okay, but I would still encourage you to retie it yourself to another surface, such as flat, thin stones. This will give you the most flexibility and manipulation in your layout over Riccia.