New tank getting established and I’m a noob. It’s a 120 with two overflow durso set up. I have a sicce silent 5.0 return. My tank will make a whistle sound every 5 minutes. I have a hole drilled in the top of my durso on both sides. I maybe noticed that when I turn the flow down it might happen less. Ideally I would like the return pump to near the 1300gph range and not the lower 600gph range. I watched BRS 52 week reefing and I saw a small hose with adjustment valve through the small hole on the durso, would that help?