Hi @Fudsey I'm also dealing with the dreaded dinos in my tank ....nothing I do has effect ...they just come back twice as hard ...my tank is a high in nutrients..my no3 has been 50 + ppm for the last 6 months po4 sits around 0.06 -0.12 ...tried carbon dosing ...vodka...tank look like $¥!+..had everything from bubble algea then cyno ..then dinos ...got the cyno from. Dosing vibrant ...tank almost crashed after treating the cyno ...that went and dinos came in its place ....so I know how you feel bro ....I've also recently heard that copepods eat dinos ...not sure if this is true ....but then my dinos aren't stingy and bubbly ...more of a dusting ....