I believe there are several ways of addressing this problem, either isolated or combined.
a)
UV Sterilizer, placed the same as
HOB, easy to install, aim at a
powerhead capable of 40-50 times in
GPH the number of watts of the UV lamp. The hard part is getting appropriate fittings, as in everything, you get what you pay for. If interested in this solution please read the following article, a bit lengthy but easy to understand.
http://www.americanaquariumproducts....ilization.html
b) Add some submerged floating plants, as Egaria Densa (Anacharis) that take most nutrients from the water column and usually outcompete most algae.
c) Avoid overfeeding fish and plants. Re-do the math behind the amount of fish food your particular stocking requires, and watch for the amount and ingredients in the fertilizer you add for your plants, avoid those with nitrates and phosphates, go for the ones with trace elements (e.g. iron).
d) Clean-up Crew: There's a lot to choose from.
I have had success with that black hairy algae by introducing a few (five) juvenile Apple Snails to help the Adult one that was already in that tank.
Ghost Shrimps, some of which may disappear without a trace but five or seven of these cute fellows are almost a negligible
bio-load.
A school of four or six otocynclus catfish, in well stablished tanks, hard to beat for anyone lucky enough to have access to them -I haven't see one at any of the LFS in my city as yet-.
Siamese algae eaters have good reputation too.
I would avoid the Chinese Algae Eater and Pleco since they stop feeding exclusively on algae and usually attack other fish as they grow old.
And of course, the never-boring schools of four of more small corydoras (Pandas, Adolfoi, Bronze...).
I'm not sure about the efficiency of other catfish, as the Upside-Down since I just got my first school of them ever.
e)
DIY nitrate removal, which essentially is a separate tank unit connected to your main tank where algae growth is encouraged so they all go there instead of your tank. There's a nice long thread about it here in Fishlore forum:
Mega Powerful Nitrate and Phosphate Remover - DIY!
Pepe
Santo Domingo