RocketEngineer
Space is big.
Mine did/does that too. They seem to come in waves. I suspect it's nutrient related. They eat until it's gone then die off.
Maybe the GFO is kicking in too to limit the algae.
Nice set up on the drill.
I missed it. Are you planning an external overflow? Why not just drill the back of 125g?
Waves of stuff makes sense. The GFO will continue for some time to come, without the refugium pulling out nutrients like it did when I full set up the tank I need something to remove the nutrients.
With an 18" wide tank, I didn't want a wide overflow box inside the tank. At the same time, I don't have a lot of room behind the stand for running plumbing. So to solve both of these challenges, I went with an internal/external overflow setup and drilled the bottom of the external box. This lets me use a BeanAnimal overflow setup without needing either a big internal box or lots of space behind the tank.
I had red planaria at one point in time. It was pretty bad. Went to Vegas and got married. While I was gone dad fed my fish and dropped something on my power cord turning off the heater. When I got back home I arrived to a tank with a temperature in the lower 60's. Extremely stressed fish and half dead corals but I never saw another flatworm. Fish and coral recovered. I lost two sps pieces though.
This was much the same, it was a case of one weekend they were there and another weekend they were gone. Because I don't have anyone I know who is really into tanks that lives near me, I have gone to automation. I have come home to some loses myself but I do my best to keep things stable.
RocketEngineer