Installing a Livewell & Washdown Pump

[tartuffe]

I am doing some rerigging on my 81 20' CC and have a livewell in the compartment in front of the battery box and splash well area. As some here know, the compartment is below the waterline so I have to pump water in with 1 pump and pump water out with the other.

It works well enough but water pumping out doesn't always equal incoming so then I have menhaden swimming across my deck.

Anybody tackle this task without any visible piping?

Also, I'm wanting to install a washdown pump. I want to have the intake for the pump the same as the livewell.

What is the best series to do this? Thru hull to washdown to livewll or vice versa?

I've seen setups where the livewell has two ports so can I run water to the washdown with the port to the livewell shut off? This seems like it might put undo stress on the livewell trying to pump 600 GPH to a pump that will only run occasionally plus the juice pull.

If I run from the washdown, will the washdown allow water to be pulled through it at 600 GPH even though its a 240 GPH pump?

Can I run the washdown to prime the livewell and then shut the washdown off?

I know, lots of questions, your experience would be appreciated.