This is seriously very impressive. 11+ Hours, I'm not surprised this looks like it took so much time.
First off all the water effects look just astonishing. The reflection of the sky and the Koi, with the little disturbances in the water.
I also really love the design of her clothes, the gradients and see through parts. And how you put in this scale like pattern, even without reading the description I could immediately see it was Koi inspired.
I also like the glowing effect it has, the whole piece has this surreal feeling.
I do however think it might be a little too cluttered. The whole piece is very nice, but I feel like the girl and her clothing should be the main focus. And even though her colours match really well, especially with the blue water.
I feel like the green of het flowers might be clashing a bit at times, maybe a different more dimmed shade of green would have worked better.
But just having the girl and her clothes, as well as the lily pads, is probably too much. I think one or the other would've been better, because both would work really well with the water and its blue purplish haze.
Also even though the water rippling effects look really nice, I think especially around the girl and her clothes they sometimes are too.. bright.
Her clothes are really really lovely, but It feels like every single detail in your drawing is fighting for attention. Which sadly makes it hard to give all the details there are the appreciation they deserve.
Overal, I'd say this is really one gorgeous drawing you made.
I hope this feedback can be off help to you. ^-^