Herbie overflow tuning

[HaZRaTTy]

Your first chamber would freak me the F out everyday, I wouldn't be able to not check the tank 1000 times a day. Water level being right to the black edging.

When I tuned my Herbie in I had no problems what so ever, I also used my emergency drain to drain into my refugium, maybe try to turn your overflow box up to the top of your Emergency drain and let it take the extra water back into your sump. It seems your 1.5 PVC can't handle the amount of GPH your return pump puts out, by routing down your emergency drain just a little it would make up for this downfall.