Adding a second return chamber to sump

When I designed my sump, I did so expecting to use an external pump through a bulkhead. I opted to make the skimmer and refugium chambers bigger since the pump would be external. I am using 1" PVC throughout with a Coast to coast overflow and bean animal style drain. External pump is Iwaki MD40-RXT







Two issues -

1) The coast to coast overflow when turning the pump on after feeding almost drains my return section

2) The external pump is just too loud and not enough space in the stand for it.



So, Instead of replacing all the plumbing and figuring out a place for the external pump, I have decided to make a second return section, one that fits the return pump, submersible this time (Sicce Syncra 5.0). I figure I can just get another acrylic box and put another 1" bulkhead in that and run pvc from the output from the bulkhead in the return section of the sump to the the bulkhead in this second box virtually double my return section volume depending on the size of the second box. The water level will be consistent throughout the two chambers and would provide more volume on system startup after feed



My one question is, with a Sicce 5.0, will I have problems with just one 1" PVC pipe connecting the two chambers? All my other PVC plumbing is 1" and I have a manifold off of the return pipe which has three 1/2" outlets for reactors. I would assume the flow through the 1" pipe on the return would dictate the flow through the sump and not cause it to back up?



I was also thinking I could put a "T" between the two in case I needed to drip or dose anything other than ALK, CALC and MAG.



Please let me know what you think. I'm running out of ideas for this setup