Battling Prorocentrum and looking for newbie UV sterilizer advice

[dumpstermermaid]

Finally put our dinos under a microscope to ID today and it looks like We are battling Prorocentrum in our tank and have been losing the fight for about a month now. Parameters were super low (nitrates nearly zero) so we upped feeding and continued to monitor. Water parameters are now in a good range, nitrates around 20, phosphates around 0.05. We tried increasing grazers (blenny, sea hare, snails) and it didn't help. We resorted to Dino X now and are still seeing very minimal improvement after our 4th dose (8 days). We got microscopic ID done today and it sounds like we need a UV sterilizer. We have a 68 gallon setup tank and sump volumes combined). Everything ive read says 1 watt per 3 gallons, so I'm looking at about 23 watts. Is there anything specific I need to look for? I saw some tube style ones that are 13 watts, could I get 2 and put one in the tank and one in the sump? How is best to approach the UV setup??? Do I need one that is contained in a pump to ensure flow, or can I use the "naked tube" style and direct flow past with fans? I don't wanna spend any more money on Sunday stuff, I'd rather just do it right the first time after taking the hard route the last few weeks. Attached photo is under 40x in case I ID'ed wrong

 

[taricha]

agree with the ID - prorocentrum.
People have had success at ~1 watt/3 gallons with a lot of different units - some expensive and some cheap. Oddly, it seems to be fine to split the watts between two units if needed. People usually run flow on the lower end 200-300 gallon/hr, and the UV units need to pull from and dump back into the display.
With prorocentrum, a short blackout of 2-3 days can be needed to get more cells into the water where UV is effective.

 

[Gools]

I may be wrong but I thought the proropcentrum was more battled with silicates and phyto and raising your nutrients and not with UV. Topshelf did a youtube video a few weeks back explaining each. Might save you some $$ if you dont need a UV

 

[taricha]

I thought the proropcentrum was more battled with silicates and phyto and raising your nutrients and not with UV.

Silicate is helpful generally, since diatoms are fast growers, good competitors, have similar requirements and niches to dinos, and in almost all cases are much preferable to grow than dinos. This is especially true for sand dwelling types, and prorocentrum spends almost all of its time in the sand & rock. But UV is also useful for any type that can be made to go in the water, and prorocentrum does have that trait.
People can argue which is the more effective intervention, and I'm not sure which I would say in this case. But either or both can be helpful.