I have an Innovative Marine 50 gal EXT tank with a herbie style overflow and ive been having a lot of trouble with my overflow fluctuating. I have a trigger crystal cube 18 sump and had originally for a couple of months used a Sicce Syncra 3.0 for my return but had been having issues with my display tank water rising every time my ATO (Tunze Osmolator 3155) turned on and would end when my whole reservoir emptied into my return pump chamber. For some reason the return chamber water level just wouldn't rise. I checked out the IVM website to see they recommended between 1000-1300 gph for that size tank so I thought to upgrade my pump to a Sicce 4.0 I had on hand that I had to turn down all the way to prevent it from draining my entire return chamber. Unfortunately the issue only seems to have been exacerbated as now when I return from work or wake up in the morning the overflow is either completely empty or has started using the emergency overflow. Id also like to note my new issue of micro bubbles in my display that i don't see in my return chamber and weren't there at all before the pump change. The only media currently in my sump is about 10-20 pounds of liverock, chaeto, TLF Reborn thats used as bio-media, and a course sponge on the bubble trap. Usually I also have a bag of carbon and chemipure blue but both are depleted and I havent been able to restock them recently. I also skip the filter socks and have it drain directly into the sump. Ive checked through my plumbing and cant locate any clogs. This issue has been running for over a week at this point and I just can't understand what's causing this to happen and what I need to do to get a stable return chamber and overflow box so I can turn my ATO back on. Other than this tank is running perfectly, fish are happy, perimeters are stable, acros are growings. Any and all help is super appreciated, thank you in advance.