In that case you should just let it do its thing. So it is red stuff now. OK. Then you will get some green stuff. Then some brown stuff. Then a different kind of brown stuff. And a little green stuff, but slightly different than the first green stuff. Finally you will start to see some small, pink, scale-like spots and things will begin settling down.
Just keep up with your regular WC schedule, make sure temp and salinity are super steady. If you get too much green algae going you cut back your light schedule a little. Reduce feeding a little.
In the meantime, you can start researching test kits for Alkalinity, nitrates and phosphates. (My faves: Salifert, Red Sea and Hanna ULR Phosphate respectively.) In the coming months you can start practising those tests. They don't matter much now as you biome is all over the place for a while as different organisms thrive, battle, succumb to other organisms.
It took a few billion years for our oceans to settle down. Give yours a year of steady, consistent input/output and all will be good.
