Plants w/ Goldfish

Hi all,

I have a 125gal tank with 5 comets and a pleco....every time I have put
plants in, it has been unsuccessful. Their constant rooting around makes
the plants surface and/or they chomp them up. It is a main feature in the
room it is in and I would love to add some color and texture to it without
having flourescent air ornaments.

Just an FYI...I know how to manage a planted tank with tropicals....As I
have a thriving 20gal (long) that has been stable for about 7 years now.
point being that I understand the basics of light, substrate, temp and water
chemistry.

I have tried to grow apongetons, anachris, hornwort, hygrophillia deformis,
and a few marsh plants and had no success.....Any ideas..

I live in Arizona and our water is pretty hard.....I don't mind softening
the water for plants....but will the goldfish be ok with the pH between 6
and 7?...(It is currenlty 7.5-8)

Thanks in advance.