someone else brought up that since i have all mosses and root feeders, and the fact that my plant mass in this tank is so low that i should look into reducing my IE dosing.
In short, I agree.
Technically, your nitrate levels look acceptable. In reality, there do seem to be a few exceptions. One of them is what I call the "buffet condition".
For this, we will be assuming specifically that organic wastes cause algae. And will be using ammonia as an example. It's not scientifically classified as an organic chemical, and neither does it directly cause algae - fishless cycling proves that. But it is the best understood waste product, and likely that other wastes work similarly.
Plants prefer ammonia over nitrate. It's easier, and takes less energy, for them to process. And it's definitely preferable to us for them to use it first, as well.
However, they cannot completely reject nitrate in favor of ammonia. Even if there is sufficient ammonia for their entire nitrogen needs alone, if nitrates are present, they will be forced to process some nitrate; which means they also process less ammonia. The higher the nitrates, the more this occurs.
Like a buffet featuring prime rib... If there's enough other appetizing items, even if they're not as good as the prime rib, you will end up filling up more on other items, and eating less prime rib. So when an algae problem can be solved by reducing fert levels to less than what are normally considered acceptable levels, thereby increasing uptake of excess organics, that's what I call the "buffet condition". It does not apply to most cases, and in fact I've only had it happen once.
But it may apply to you. You do in fact have a lot of fish, and therefore organic waste. Plus limited plant mass. It could be solved by altering your scape, getting rid of fish, or reducing your feeding; which I'm sure you'd rather avoid.
So reducing your dosage is certainly worth a try. Fish food, and therefore waste, provides mainly nitrogen and phosphorus; so those ferts are the ones you want to reduce most. Potassium and traces, not so much, if at all.
Increasing plant growth can also solve it. Even at your current lighting, and despite that more light typically encourages algae, adding more light may
have positive effect by tipping a more important balance. Strong emphasis on "may".
And of course, CO2 and flow. Your CO2 levels seem ok. But your flow isn't, either by the numbers, or by the odd effect adding the Koralia had on your fish. I have no clear explanation at this point for that. Maybe it was still a minor increase in CO2 at the level where the fish reside, coupled with low oxygen due in part to very low surface agitation; in which case pointing the Koralia at the water surface should work better. Or maybe it's kicking up an accumulation of organic wastes from the substrate, which are depleting oxygen. If anyone reading has any better ideas about this, please chime in!