New L4

Yup, see what happens. When you do your first harvest, make it a very moderate one. Pull by hand and see how much comes off. Try to leave a decent amount on the screen along the top edge as that will migrate downward. you can be a bit more aggressive along the sides and bottom edge though.

 

Very nice, good recovery! Always good to try. I would still try to leave a good layer behind when harvesting.

However if it does come off easily - don't worry. One of the things I've learned is that when algae doesn't have to stay attached, it won't anchor strongly.

In the case of my scrubbers, or really any unit that allows 3D growth, the weight is taken off the growth mat. Add in the false bottom, and the algae mat becomes a mass that is rather self-supporting, and it stays in place (the false bottom keeps it from getting pulled down the drain) so it doesn't "need" to attach strongly to the screen.

I've seen this effect in multiple versions of my scrubbers, I'll pull the screen out and the the lower half comes out pretty much clean (but not white...looks like it's been scraped), the algae stays in the box.

 

Recovered well, thankfully!

 

That's actually not a terribly bad sign. I get that when I let it go for a bit too long, but for me that's usually more like 18 days, that's monster growth for 11 days!

 

Oh no, not again!!