What is that plant?

[chka]

I have problem with this plant. Its leaves are melting and it drops leaves. The it makes new branches with new leaves and then again it drops leaves. The light is good, co2 seems to be enough for other plants.

So what exactly this plant is and what does it want? 🙂

Is it rotala sp butterfly?

 

[Mick.Dk]

Alternanthera reineckii !![DOUBLEPOST=1407414047][/DOUBLEPOST]Rotala mac. 'butterfly' has way smaller and thinner leaves - and will grow far darker purplish-red colour.

 

[Andy Thurston]

Probably wants more co2 like the carpet behind and to the right

 

[chka]

It was recently moved from another tank together with carpet so carpet still recovering. But it was very healthy in previous location but that red plant was the same