Odds are they won't be the only ones to find the feeder. You now have a choice to make. 1) Continue feeding and get the tilapia big & fat for maximum breeding now, increase your numbers, then make a massive dent later on down the line by turning off the feed. 2) Hit the filamentous hard now by turning off the feeder. 3) DO NOTHING ;\)

My feeder will stay on, but I'm interested in weight gain 1st, filamentous is a distant 2nd.