Here’s what worked for me after battling this stuff for the better part of last year:
No water changes. I bought a UV sterilizer and connected it to the tank. I did a 5 day blackout. During the blackout I would blow off the sand, back wall and rocks to suspend the dinos in the water column, making it easier for them to go through the UV sterilizer. I also dosed 1mL of h2o2 during the blackout and for 3 weeks afterwards. After the blackout, I did a large water change (30%) and I only ran blue lights for the next 2 weeks. I also brought my nitrates and phosphate levels up to detectable levels since I had a lack of nutrients in my tank which caused the dinos to continue to thrive. I haven’t seen dinos in my tank in almost 3 months. Now i just have gha that my snails and crabs eat up.
most importantly though, you’ll want to identify the type of dinos you have so you can best prepare a plan of attack.