I just did a water change, but i checked a couple fays ago and water parameters were perfect. Ill check in the morning, i only have two fish and feed the very little.
Well most of what you have growing is coralline algae (or at least looks very similar to it). Algae can also skew test results for things like nitrate and ammonia since they consume it as it becomes available. I think you'll be okay if you keep an eye on it and let your tank mature some more. A few more snails such as trochus, astrea, and margarita snails will also help.
In the meantime, +1 to what Nathaniel suggests: CUC clean up crew to help manage algae: snails, crabs (Blue Leg Hermits) and maybe a fish or two to do some work for you: algae eater like a starry blenny; and a sand sifter goby to clean the sand. Toothbrush, filter pad/sock changes to keep up with the algae cycles. Here's a great place to get CUC. If you use their calculator reduce the quantities because it's a new tank and there won't be enough algae for the full crew and they could starve and die: https://www.reefcleaners.org/cleaner-packages-with-free-shipping
Nice. That's the beginning of the good coralline algae you want. See if you can gently brush it off with a toothbrush if so it's nuisance algae; if it stays it is the good stuff.One thing i noticed also, it lots of purple spots on that rock under the algae
That's going to be your call. If too much algae growth is happening, you could cut it back to 8 hours or so and adjust from there. Every tank will be different. I didn't see any corals in there yet. So it's ok to play around with the photo period of your lighting without fear of hurting corals.
