Detached MC carpet

[Daneland]

A very large patch detached from the substrate.I put a piece of wood to keep it on the substrate.It is not really thick, there is a lot dark green algea on the surface but it was looking healthy.
What should I do ?Should I just remove it and replant as small clumps? Or is there any way to re-attach it?

 

[Zeus.]

Replant on small clumps
The MC doesn't look to happy in the pic you injecting CO2?

 

[Daneland]

Replant on small clumps
The MC doesn't look to happy in the pic you injecting CO2?

I thought as it has spread well, it was doing OK> Yes I do inject CO2 but I guess it is more of a circulation problem. I cant pay enough attention to a high tech tank, it is too demanding for me. I just inject CO2 and add some ferts. But I dont bother with the rest. But apparently MC just disagree with it. Reattachment will be a pain. My 4 years old cat litter substrate does not hold it nice and tight. After planting them, most of them start to float again. Perhaps I should change aging substrate too. May be not the whole substrate.Any inexpensive substrate you can advise?

 

[Zeus.]

MC can be a pain to get it to hold in the substrate esp if the MC doesn't have much roots