LeighMo wrote:

The tank is
heavily planted, with a nice carpet of dwarf hairgrass filling in.

Sigh. Do you have any pics?

I love the look of hairgrass, but it won't grow for me. "Difficult" plants
like glosso and Lilaeopsis do, but not hairgraiss, which is supposed to be
easy

Leigh,

It is anything but easy. The fiirst two shipments were half dead, but I managed
to pull out maybe 30 blades of living grass and cultivate them. Then I found
some at a fish store in San Francisco. It is slowly spreading, but also slowly
accumulating all the crap, sorry, mulm from the tank. And if there's even one
variety of active algae in the tank, it attaches itself to the blades.
Sometimes I have zero blue-green algae (cyanobacteria) anywhere in the tank
except on a few blades of hairgrass. BBA loves to colonize the tips. In short,
it's a mess.

BTW, the variety I'm referring to is Eleocharis acicularis