most of the planted tanks we have grow algae its keeping it under control is the key well your phosphates can be coming from your fish during feeding or overfeeding if you foreground is covered algae will not get a chance to grow i have many open area's in my substrate where algae will grow after a long time like green hair looks nice sometimes you can get rid of this easy by moving substrate around mixing the bottom to the top until i have my foreground covered i know i will have to deal with this at times now its getting more under control just introduced more plants but my opinion is to clean all your algae good when it comes back clean the wall good even get crazy and clean you filter tubes helps alot and let is grow in your substrate in one section and leave it it wont get out of hand this way until you cover your foreground and keep everything in balance