Brown Algae

Hi all, First post so here go's.
Decided to get back into fish keeping in April 2016 and for a year had no problems with Algae but then the dreaded brown one appeared.

Ammonia 0, Nitrites 0, Nitrates 20-40 (tap water has 20).

kept on cleaning, cleaning and more cleaning with no success. I was at the point of giving in and selling up but decided to buy a bag of API Prevent Algae Powder size 5. Placed this into my 64Ltr tank in a separate small filter.
Bingo, no more brown Algae. Packet says replace after 4 weeks but was still working after 18.
I have no live plants only silk ones.

There was no sign of any algae at 18 weeks but changed it anyway.

Hope this info helps others because hobby's are meant to be a pleasure and not a pain.

ps: i keep my silk plants clean with baby bottle sterilizer. In a bucket for 24 hours, no need to scrub.
     Rince well before placing back into tank