Dreaded GFO sediment

Is what I’m dealing with normal? Here’s my equipment
HOB skimmer
sump with some live rock in it
GFO in sump
Purigen in sump.
Canister filter with purigen in it
That’s all my equipment.
I get algae on my front glass each day that I have to clear. Not a lot but enough in some spots that I can notice. 2 days would cover entire front glass with a thin film of algae. But my sand gets algae every 4-5 days. I only have 3 fish in my tank (2 clowns and a tang) so bio load is small even though tangs poop a lot. Don’t feel that I overfeed. So why don’t I have algae free tank for the most part? I know algae is good but I get super annoyed when I see it on the sand. I siphon it up and end up losing sand. Think its diatom algae
I do 10g water change weekly
Am I missing some gear to help or is this normal? Do you guys have to clean sand once a week? I see pictures with people that have crystal clear water and zero algae.

 

I will look in to purigen. I didn't know it was easy to recharge. I'm running carbon as a filter pad for now but I will put some in a reactor later today.
Great info everyone. Thanks for posting.