Melanotaenia, plants will be just as good as filamentous algae for absorbing nutrients and will be far less dangerous. On one occasion, ages ago, we kept a tank in the house that became overrun with thread algae. The fish kept getting trapped in the strands of algae, each up to 5cm long, and getting smothered by it. The last fish to get tangled up and die was our bristlenose, my favourite fish at the time, who couldn't eat it because it was so thick.