Hi bhavik,
I have gone back through your threads here over the last 3 years and it seems that you have always had problems with plant growth or lack thereof in this tank and the 200 litre tank you had previously. It has occured to me that your tank/s have always been hugely overstocked with high bioload fish, a large pleco appears in some photos for example, Severums, Jewel cichlids, Discus also lack of good filtration on these tanks, Fluval 206 on the 200 litre and a Fluval 306 now on the 240 litre.
Maybe you should not think about having a high tech planted tank with the Discus, go low tech, low lighting, use just epiphytes and some driftwood, increase the filtration by adding another canister filter. Concentrate on having a healthy tank with healthy fish within it.
For a planted tank, why not use a smaller tank, 10 - 100 litres, high tech, Co2 injection, good lights suitable for the job and a very light stocking of low bioload fish or even shrimp.
Following the advice of the very experienced people on here would be a good thing to do. For example you were advised with your spray bar to have it about 2.5cm/1 inch below the water surface to create water movement to help with gas exchange and yet in some photos the bar was positioned about halfway down the height of the tank.
In my opinion you need to choose which route you wish to go down, follow advice from those who have already made mistakes and have learnt from them, get yourself a good water test kit, get more filtration, be patient in your endeavours.
I am no expert, I have had and got planted tanks, low tech. I will be picking the brains of anyone and everyone when it comes to doing high tech Scaped tanks and I will be following their advice which is freely given out of the goodness of their hearts. I personally would not ask for help/advise then ignore it and then come back time and time again asking for the same advice.
Sorry if this sounds harsh to you but this is my advice to you.