What's mowing down my dwarf hair grass?

[elwaine]

The dwarf hair grass in my tank was growing beautifully... spreading more than i wanted it to... and then, out of the blue, I began to see lots of grass floating on top of the water, as though it had been selectively mowed. The floating shoots are a nice bright green. Each morning there is a new crop of shoots floating in the tank. Any ideas about what is causing this?

I can't understand what would clip the shoots near the bottom and then not eat the rest of the grass... but some creature seems to be mowin my lawn at its base.

I have RCS and Otos, but they never did anything like this. I also have Gertrude's rainbow fish, but I doubt they are the grass gardeners.

I also have some tiny shrimp-like things about 1/4 inch in length that got into the tank with some daphnia that I fed my fish. They do not look at all like the RCS. Instead of straight bodies, these gray creatures are almost always curved in a "C" shape.

Thanks for your help...

 

[timwag2001]

i agree... beer is not just for breakfast.

are those the only inhabitants of your tank?

 

[elwaine]

are those the only inhabitants of your tank?

I have snails... but they never cut the hair grass before. At the rate at which the grass is being destroyed, I'll probably have no dwarf hair grass left if two or three weeks.

 

[JustOneMore20]

So the floating hairgrass has no roots, right? I have pieces of hairgrass floating from time to time (no roots), but not as often as you. But, I don't know that any of those fish would be doing that from your list. And the floating parts are green and not browning at all?

Has anything changed in the tank? CO2, fert dosing schedule, water change schedule, light?

 

[elwaine]

Hi Kristin...

The floating grass is green, not brown. Water parameters are stabile except for a change in GH. I increased the GH from 5 to 10. This was done gradually.

I could understand the death of the hair grass if it was either browning out or not reproducing. But the floating blades of grass are bright green, and the hair grass is putting out new runners all the time. There has to be a mechanical reason for the "cut" blades of grass.