I tested my tank with API liquid master test kit

AbbeysDad

Not to contradict our resident expert, Byron, but I see little rooted plants in your tank. As such, you should indeed remove excess detritus on the substrate. In your case, it appears you have a gravel sand mix, so you would likely just hover over the surface to pick up the crud when you do your weekly water change.

Byron

Yes, I agree. I didn't see the tank. You should have plants that are rooted in the substrate to help with the biology. Swords are excellent for this as they have extensive root systems. This is important for a couple of reasons. Not only do substrate-rooted plants use the nutrients resulting from the breakdown of organics by bacteria, but a lot of oxygen is released by plants through their roots, and this in the substrate prevents dead spots. Like I say, there is a complex process going on down there, very important to a healthy aquarium.