Waterbox marine x overflow help

[Fredrxn]

Hello guys my marine x 110 been up for about 2 days .....I am having problems with the overflow and the gate valve.i sit the gate valve so the water is just under the emergency drain it will stay there for a hour or so then it will start overflowing the emergency drain cuaseing my ato to kick on. I did modified the main drain for my fleece roller, will this be causing the problem? See pictures below. Also maybe my return pump is to weak? Seems like not much flow coming out of return nozzles return pump is simplicity 1600 dc... thanks

 

[Fredrxn]

Anyone know why this is going on?