You guys are exactly right. The gutter guard is changing the open area of the weir. I may try and lower or remove it. The neons hung out up there when I got them but now see to avoid it. I'll keep you posted.
You guys are exactly right. The gutter guard is changing the open area of the weir. I may try and lower or remove it. The neons hung out up there when I got them but now see to avoid it. I'll keep you posted.
The posts above provide some good guidance, and I also conclude that only a small difference in height of the display tank water level will occur if you remove the gutter guard. When I've raised small 1.5"-2" Frontosa in my 450gal, I adhered a thick ~2" and very coarse filter media, like this Pond filter media to my overflow weirs, which was coarse enough to not restrict the flow, and thick enough so the small fish didn't get stuck/suctioned to it.