Huge thanks for the tips. Too bad my Ambulia bends to the level of water so I proly will double dose it first. or 2.5 times, give it a shock treatment and see how it goes.
In terms of Phosphate, will adding liquid fertilizer do ? I am having a 300L tank, width 150cm, height 53cm, and I am on 4 T5 tubes 40W each, 1 power glo, 2 OSRAM 865 and 1 OSRAM 840, not sure if the light is too strong.
Weird thing is that, I have a 60L tank, running on one OSRAM 840 light, and ambulia in it is perfectly fine, grow like crazy, no algae in the tank at all. A lot duck weeds though, I hate duck weeds.