I wouldn't lower the salinity that low enless I had a refratometer, hydrometers arn't as accurate and you have a chance of taking the salinity down to dangerous levels. Cleaner shrimp work great, I have heard good things about the uv but don't personally have one. Since you already lowered it raise your salt level slowly over time, take your tank water and mix in salt. I would mix in 1/4 cup in at a time and do it again in few hours but I don't know how big your tank is. I would raise it slow over time, because I have made the mistake of raising to quickly and acclimating to fast.