Need help with Algae PLEASE

[05nismoz]

I have this brown algae on my glass. Its brown and stringy . I have tried every thing to get rid of it. The only thing that worked was a total black out for three days and the algae was gone for 2 weeks. Now its back stronger than ever. I clean it completely off the glass and 2 days later its everywhere. I have cut back on feeding to every other day. I have added 2 phos-ban reactors one with phosar hc and the other with carbon. Cut lighting back to 7 hrs a day. I do weekly wc of about 20+ gallons of RO/DI. Nothing seems to help. I really would like some help here. I am getting very discouraged.

Tank parameters and equipment:
180 gallon running 4 months
200 lbs live rock
240 lbs. of live sand
3600 gph dart pump
2 korlias 4
Geo Kalk and Calcium reators
225 coralife super protein skimmer
54 watt uv
RO/DI water
7 fish, 2 shrimp, sea , 2 sea cucumbers, brittle star, snails and grabs

Salinity:1.025
temp: 76
Ph: 8.2 - 8.3
calcium: 420
Alkalinity: 9 dkh
Magnesium: 1350
nitrate: 0
nitrite: 0
P04: 0

Here are 2 pic that are not the best. The algae is on the glass.
thanks for any help.