Your rock is hitting the saturation point on nutrients. You’ll see algae growth getting rapidly worse and eventually you’ll see measured phosphates going up.
You need to get to work on aggressive nutrient export. Either a big enough algae scrubber or a ball of chaeto in the sump with a sufficiently powerful light (Kessil fuge light, AI Prime Freshwater, dedicated hydroponic grow light at least 90w+ etc.).
Alternatively you could go with carbon dosing, Zeovit, or GFO, but those seem to be less popular right now.
You really need to start sucking nutrients out and water changes won’t do it. It’s about to get frustrating and the sooner you get them gone the better.
You need to get to work on aggressive nutrient export. Either a big enough algae scrubber or a ball of chaeto in the sump with a sufficiently powerful light (Kessil fuge light, AI Prime Freshwater, dedicated hydroponic grow light at least 90w+ etc.).
Alternatively you could go with carbon dosing, Zeovit, or GFO, but those seem to be less popular right now.
You really need to start sucking nutrients out and water changes won’t do it. It’s about to get frustrating and the sooner you get them gone the better.

