Hmm, great point on the nutrient IMPORT side of things. Seems obvious but I never considered that side of things. And I have everything to grow it, and wouldn’t need to buy sheets.
But then every morning I’ll have to get my hands wet pulling out breakfast for the fish. I’m considering it. Will have more room in the fuge on this build.
I do think it becomes significant in larger tanks with a ton of tangs and herbivores. I have seen people go through 2 sheets of nori a day... That will build up over time. Yes I paid like 40 bucks for sea lettuce and red grac from algae barn and don't plan to spend a dime more on algea foods.
I am lucky enough to have that tank divider in my fuge. As you can see from my photos, once the lettuce was large enough I put some over the top of the divider so I don;t have to get my hands wet to harvest.
I got an idea though for your case. If you have to algea clips. One can be used for display feeding. The other mount high enough in your fuge attach a piece of algea and let it grow out from the clip. Once it is large enough some will float at the top for easy daily pickings. Ulva grows at an alarming rate... so I am sure you will have still throw some out.
I have also noticed ulva seems to be my pod farm in comparison to cheato. So every meal pods get directly placed in the DT, curious if my leopards will being to notice.