Your ammonia and nitrite are high, and indicate that your live rock isn't doing it's job. Have you thought much about "flow"? That is the term used to describe the amount of water motion in the tank. It's important for several reasons, but primarily because the nitrifying bacteria on the surface of your live rock must have a sufficient supply of water to bring food (ammonia and nitrite) and take away waste (nitrite and nitrate). Any live rock surface that is getting low or no flow over its surface will not be able to support many bacteria and so isn't helping with filtration. Low flow is like having less live rock. How much flow do you need? They say "at least ten times the volume of the tank per hour." But how do you measure flow? I think people calculate the number of liters per hour that each of their pumps delivers, and those numbers together to get an idea of "how much flow" they have. Your return pump probably has a flow graph posted on the internet showing Liters/hr as a function of "head". Head is the vertical distance that the water must be lifted by the pump, plus the amount of friction caused by the plumbing (add 5-10% to the vertical distance lifted to account for plumbing friction). Use that flow graph (chart, diagram) to get the flow from your return pump. Then add to that the number of liters/hr that each of the powerheads you have in your tank claims to produce. If the total is around 10 times the number of liters in your tank, then you probably have enough flow. Such a measurement is obviously quite flawed because it ignores many important factors, like how much live rock you have, how it is arranged, and where the flow is directed. Just remember that you don't want enough flow, so that particles will stay suspended in the water, and not settle to the bottom or on top of your live rock. Then it will eventually be removed by your filter sock or skimmer. Also remember that you don't want dead spots (places with little water motion) so arrange your live rock so that water is "blowing" over as much of its surface as possible, and blowing hard enough to blow off any "dust" that might settle on it. Avoid the temptation to lean a pile of live rock against the back wall, because it makes it hard for water to flow around and between the rocks in the pile.
You'll read a lot about what "kind" of flow is best. A powerhead can blast too hard on one spot, and not enough elsewhere, so people often point two powerheads at each other, or point a single one at a glass wall, so that they create a chaotic, random, flow patter. That seems to help.