Small tanks is what I know best. What size is your tank and how old is the set-up?
At first look the tank has a natural feel and look to it. I like the choice of driftwood and the Hatchet fish goes well with this set-up.
Now to what I see wrong with this set-up.
This set-up has a balance issue with colors and the use of space.
The background plants are too tight, need more space to grow. You can do this by shifting your set-up forward and loss some of the foreground.
Also trimming down and replanting each species of plants to different heights helps create depth.
You have too much green on the right side cause by the stargrass. You need to tame that bush.
I mostly use stargrass as a mid level plant since it looks better viewed from the top. Try replanting some in the mid center and bring some plants on the left to your right side.
The driftwood in the middle is too centered and straight up. Move it over to the right and lean it alittle to help out the right piece of driftwood.
That also helps balance out the right side by taking away from the left.
The rocks on the left creates a bald spot and will not go well with the Sag. foreground. Remove and add more substrate to build up a hill on the mid left side in front of the large driftwood.
This will create a flow following the curves of the large driftwood down from left to right.
After it's all said and done a balance set-up with a good flow is what makes a tank.
A flow to me is a smooth transition from lines to colors when veiwing a tank.
This tank has a good chance to do well in a contest when done right.
Good luck with this tank, love to see how this tank turns out later on.
thanks, about the advises, this is a 30L tank, the triming job is hard to do when these guis are ready to jump in all means. This set-up is about 3 months, with one or to modifications. In the begeaning i put many anubias b. nana, but they whent to large.