Looks like you have pieces of filter pad in your rock? Did you buy some pods
? Btw welcome to the most addictive hobby ever!
I will agree with everyone but not going to be so forceful. Your doing great and most of us are guilty of the new sw
hobby rush. With fresh water, people tend to setup and buy fish the same day. Waiting on buying your first corals and fish just isn't easy. Setting up your first sw
tank makes you anxious and Even us "advanced" sw
people have done this when we first started the hobby (Not all but most)!! It's just a learning experience.
Like others, I would also recommend a little more rock. But keep in mind that EVER tiny thing you do to your tank, your tank knows it and responds in chemical changes. if you add a rock,fish,coral or even MOVE a rock. The tank knows it. I can stick my hand in the tank and the skimmers go crazy.
Base rock is a great idea that some have recommended. I placed 20% of LR
on top of base rock when I started my third system. A year later you can't tell the difference because it's all covered in life.
As for making your sanded not so "fine", crushed shell or (my preference) aragonite works well. It's really a personal preference. Just be careful not to get the sand bed to deep, this can cause a huge headache in the long run. Sand beds are like an aquariums trashcan. Everything settles and begins breaking down in the sand. The deeper it is, the more waste it holds causing perimeter problems. Unless your a good "floor cleaner"
Great looking tank, i wish you the best!