My susn sun is rated at 525 g/hr. Lets say 400gph with media. Cascade 1200 is rated at 384 gph. With media and spray bar lets say 250 gph. The aqueon 700 fan is 700 gph. So thats 650 gph filtration turn oover and another 700gph of flow which is 1350 gph of turn over flow. I think flow is good? I had to adjust them in a manner to where they werent tipping my plants completely over with flow. You can see the algae sway on the substrate with this flow but is attached to the rocks.
i will do my weekly 80% w.c. On sunday. Get more plants and cut dosing to see what happens.
I usually like to target at least 10x turnover. I think you're about there. No, need to add more. I would look at how the water is being circulated. It seem like isn't enough close to the substrate. The flow is your co2 and nutrients distribution. If you have good flow, IME algae shouldn't been sticking to your plants.