Harshit I'm just now reading this for the 1st time in late November and wondering if your plant ever bloomed, I have the same trouble here with my lilypads not flowering as much as I would like. The lady at my local pond store told me that lilypads need to be at a particular depth in order to grow the flowers we want. I guess if it's too deep the plant uses all it energy growing it's pads to the surface because it wants the sunlight, so maybe try to raise it up a little closer to the surface. It's something you can research on the internet in your spare time. I didn't bother doing it myself because most of mine are not in pots, they are just rooted to the bottom. Great looking plant I must tell you , huge pads, good job!
Yeah, they bloomed within 1 or 2 weeks after posting this thread.
However the depth was not the problem as my pond is not more than 3ft deep and the container was place below 30cm of the surface. Actually I wanted to lower the container but there was not enough space to place it. I think it takes time to develop the leaf and root system properly first then it starts blooming.
Now around a month ago the lily pads were getting smaller and smaller in size. I observed for few days and then took the container our and started digging it.
The whole container was heavily filled with roots, so I had to remove the roots and replace the sand and fertilizer. I used compost this time, just to check if it works for lilies.
Now the new pads growing are like the ones shown in the first picture, when it was planted in tub.
You may find it crazy, but something similar I've observed in tomatoes also, ones grown in small pot with less soil less water. started giving flower earlier and also started fruits so early. while the plants were not looking so healthy.
And the plants grown in ground with proper soil and watering, are so huge and healthy before starting the flowers, they're getting taller and taller. (I've only used some vermicompost for both and nothing else)