Put in some more hiding spaces and you will be fine. Either cave type decorations or more driftwood. Keep zebras away from aggressive plecos btw phantoms and Goldie's are some aggressive dudes
Plecos will seek after the easier food, if there is uneaten food in the bottom of the tank they will gladly eat the food and not touch the algea. You should get more plecos ;) you can never have too many you know!