suggest me a background plant that wont grow TOO tall

I was going to say dwarf sag as well- it really doesn't stay dwarf in my tanks, but it does get about 12" tall. I also love the look of cyprus helferi its much more compact than blyxa a. and a nice bright green color and its a slower growing plant- no runners to remove etc.
 
I have both dwarf sag and dwarf sag looking sag that get tall. mixed together, they look fantastic. I've read about some getting tall over time etc, but in my experience the ones I have that are small stay small, and sprout off small plants. the tall ones sprout off plants that grow taller.
 
I like crypt. spiralis, just a little bend over the top. Rotala indica or any stem would look nice but need regilar trimming. Sag has never grown to more than 8 inches or so for me, mostly ~2-3.

Any anubias except nana or java fern attached to wood or rock can work well too.
 
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