STORY TIME - Water Parameters for a Community tank

[BlueMeanieBettaFish]

Hello! I've posted before, it's been awhile. Currently, I have 5 Zebra Danios, 5 Emerald Cory's, a Mystery Snail, And a Single Silver dollar. Those who've seen my previous posts know I've been here before, I'm now 18 and know alot more. I only have a single silver dollar, because inexperienced me couldnt take care of all I had, and he, was the sole survivor of my inexperience, but now that I know what im doing, my fish are all well, and the silver dollar occasionally schools with the Danios, believe it or not, as for the Halfmoon King betta, he gets along with everybody, the silver dollar keeps him in check, funny enough. I've posted my water parameters, I dont have a planted tank, but I want one, and I want a Crawdad. What should the GH and KH be adjusted to for this? I wanted a Carpeting plant. I know Cory Dora's dont go well with Crawdads but, my tank so far is a miracle, I mean, a single silver dollar? A betta fish not being aggressive?

PH: 7.2
Ammonia: 0ppm
Nitrites: 0ppm
Nitrates: 20ppm
KH: 100ppm/5.6kh
GH:25ppm/1.5GH

 

[Regalz]

I love when my male bettas get along with other fish!
I also have one that survived my inexperience, its a white cloud something lol
Its been my betta companions for a few years now.