We have a Dino problem too. We have manually removed all that we can see but we know it will come back so investing in the UV. Did you use Dr Tims Waste Away in conjunction with the UV to get rid of the Dino’s?
I fought small cell amphidinium dinos for a year...raised no3/po4, stopped water changes, dosed silicates, added pods like crazy, siphoned infested sand and rinsed in tap water and peroxide (let dry and then placed back in tank scattered around)...I was able to control them somewhat, but they were always present! So, I performed the Elegant Corals dino/cyano treatment (which uses microbubbles, Waste Away, Bottled bacteria and extremely close monitoring of the pH for 7 days) and bang, it knocked my small cell amphidinium dinos! I did end up with a huge green cyano outbreak that is still somewhat present, but that I can control. After the small cell were controlled, the ostreopsis dinos started to flare up...initially I only had those in one spot on a high rock near the light...but they started all over the tank! I could have done the Elegant Coral treatment again (many require 2-3 times for complete control), but got a great deal on an Aqua 57w UV unit locally from another reefer. Once hooking that up (pull from the DT and return to the DT)...bam, the ostreopsis were gone! It's been many months now with the tank looking beautiful again...except for the cyano that is still occurring. I've started back into regular 10% water changes every 2 weeks with no resurgence of dinos...and now all corals are back to looking really happy again!
If you attempt the Elegant corals treatment....follow directions explicitly and work hard to get the finest mist of microbubbles possible! It does work...but pH has to be monitored very closely since dropping pH indicates a rise in CO2 and fish can be effected.


