Help, can't figure this out

[Coleus]

Ok,

So i set up the secondary tank that hook up to my main sump. The drain is 1 inch and the return is 3/4 inch. It is power by the rio2100.

Every one or two days (can't determine exact time yet ) I got a wet floor because the secondary tank water is being overflow. I test this theory by stick a paper beside the side of my tank and it is wet when this happens. It is not because the tank was leaking because i am sure i reseal it nicely after it got leak the first time.

I has been monitory the water level of the tank but don't see the water level increasing that cause the overflow, it just randomly happen.

Anyone know why?

Thanks for any helps