E Bleheri turning yellow

[ehlim]

I have an assortment of plants, such as, H. Difformis, H. Polysperma. H. Corymbosa, Combobas, Amazon Swords, Vallisneria in my 1-week old 4 footer. CO2 is at 4-5 bps and 5 x 54w lights for 7 hours. All the plants seem to be growing well except for the E Bleheri, which are turning yellowish. What can be the cause of this? Just did the 1st wc yesterday. Should I commence to use the Ferka liquid fertiliser? Tks.

[StanChung]

the other plants are ok? do you know if the plant is an emersed or submersed form? could be dying off...does it have new leaves?