If I'm supposed to do the main job to remove/prevent the algae, what's the point of having a gadget which is supposed to do it instead of me?
In my case it was totally useless, I got rid of BBA with healthy plants and adjusted photo period and light intensity. Green dust algae is present on the glass with or without a magic device. Btw. has someone an explanation of those various modes on Chihiros doctor? They sound incredibly nice, but so far no one could say what they do and how they differ (shrimp, plants, fish,..). I mean, doctor is fun, bubbly cloud is attractive, device is quite cheap, but I wouldn't buy it again.. In each case, I'm still interested in reading some scientific proof about its benefits and methods of working - if you happen to find something, please share it.
I'd say that going with an UV is a wise choice. If you have a bit of free time and some basic skills around electronics, you can build your own (very cheap) reactor..