as far as a clean substrate goes, making sure that there's flow around the rocks is the main key. You can see that there's no rocks piled against the wall, that means that detritus won't get trapped there.
I used to think it was total BS, and a cleanup crew was just another way for LFS to siphon money and would never pay 40 for a couple of snails. But a good CUC goes miles in keeping a sand bed clean. I use over one to two hundred Nassarius Snails, 2 small conches, and several pitho crabs. They keep my 4" DSB clean and free of algae, but at the same time my sand bed is so full of life; every inch covered in spaghetti worms, sphenoid worms, and pods . Try to stay away from sand sifting stars, they like to clean out all the good stuff in sand.
Just the other day, for example. I took out a rock that i'd had buried almost completely in the sand. I expected the horrible necrotic smell from stuff that was buried. What I got wasn't just no odor, rather the rock was actually clean on the bottom! the odor comes from bacteria that gets buried and killed, a good sand bed contains things to eat the bacteria.
Hermit crabs are usually the best to clean algae from rocks, then nooks and crannies. a tang helps too, I keep a 60 gallon Macroalgae tank plumbed with my 180 and haven't had a single algae takeover problem in the 180.
that being said, a fuge is also a great thing in order to help with nutrient control. You can use GFO to suck as many phosphates as you can from the water, but that also reflects on SPS and coral growth as they like some nitrates and phosphates in the water to grow.
Unless you run copper, Algae on the glass is always going to be an issue. You can use an algae scraper to fix it, I personally prefer using the Tunze Care Magnet since it doesn't have the pad that sand likes to get stuck under, it's entire contact on the glass is made through two blades that use pressure to scrape the algae off, also allowing it to clean up to and under the sand. Doing this about twice a week matters because the thicker algae gets, the harder it gets to scrape off and if you use a scraper, more pressure could lead to more or deeper scratches.