strangeways, are you able to get a temperature reading of the air around the plants?
Biobizz all mix states it has an EC of 2.4. That's hot stuff everyone. The plant has dark green leaves with leaf tip and edge death, most likely caused by over fert. Not only is alienwidow not on same page, they're not even reading the same book. To tell someone they have to feed when leaves are that dark green and dying shows that the alien is lost.
If tested with a Hanna meter, 2.4 is equal to 1200 ppm. Eutech and Truncheon will show 2.4 as even higher.
http://www.manicbotanix.com/hydroponic-grow-guide/ec-to-ppm-conversion-chart.html
I know over fert when I see it. Heat could also be an issue in this.