Well - this is going to be a bit biased, so take if for what it is, but heres my opinion.... first off, I have no idea if a chinese algae eater will eat your nasty algae or not.... but, before even trying that - I'd ask, what kind of other fish do you have in the tank? Heres why I ask:
About a year ago, I was at the LFS - they had this awesome chinease algae eater, about 4" long - I thought, what the hay - he's awesome, hes a friendly fish, I will buy him, I have the room - and so I did.... tossed him in my planted 125g after a quarantine period... a couple days later, I had a praecox rainbow die.... I checked my water quality, etc. everything was good, couldnt explain it.... a few days after that, I had another die... then the final straw, I had a track eel die (I was very attached to this little guy)... I noticed these events all seem to happen AFTER I got the #$%^&ing algae eater.... So I did a little research, turns out - they have been known (once they reach a larger size) to eat the slime coat off other tankmates, causing death... Needlesss to say, I was SOOOO pissed - I took him back to the LFS, they woudlnt refund me, infact they were hesitant to even take him back, giving me the same reason that I just experienced (but neglecting to tell me that when I purchased him)!!! So, long story short, I never returned to that LFS and I will NEVER buy one of those <insert mean name here>'s again!!!!!!!!!!