my 28 gallon nano is dealing with a nutrient/algae problem not really sure which. this like brown slime algae is covering the rocks. its not cyano. i just treated for cyano because there was some along side this algae using chemiclean. corals arent looking great so im pretty sure its a nutrient issue. the tank is "over stocked" but it always has been. before all this happened there was a blue spot puffer, 2 garden eels, a clown goby, a perchlet, and a jawfish. i got rid of the toby recently and added a orange spot shrimp goby and a sand sifting goby because of all the brown slime algae on the sand. the sand sifter cleaned up the sand great but its still all over the rocks. tank is running a eshopps protein skimmer ( see here https://www.amazon.com/Eshopps-Hang-Protein-Skimmer-PSK-75H/dp/B006OOQKHS ) which says its good for up to 75 gallons. in the past i have had a few more fish in the tank than i do now and there was no issue. i do water changes on it once a week (about 2/5) and feed once a day. phosphates read close to 0 but im assuming thats because the algae is using it all up? the tank has dealt with a lot of algaes, first it was bryopsis but fluconazole fixed that up, then GHA and now this brown slime algae. i removed it all from the rocks a few days ago using a toothbrush and siphon and it just keeps coming back. only thing that has somewhat worked is the sand sifter goby for the sand. I also added a tuxedo urchin i moved in from my frag tank. the softies are all upset (including xenia GSP clove polyps and toadstool) but LPS (frogspawn miami hurricane chalice trumpet coral) are all doing great, which i find kind of odd because I thought it would have been the other way around. what do yall think the problem could be? anyone have any experiences with this brown slime algae? it is cyano like but not cyano.