Quick ballast question

[mevirga]

Hello-
I'm installing a supplemental and independent ballast system that draws from the raw water intake on my '99 Air. It will fill/drain via a reversing puppy pump plumbed to 2 bags. I will TEE a vent line from each bag into the bilge pump lines. Question: do I need check valves on the vent lines?

Thanks for the help.
Mike

[Chexi]

I would be more worried that your sac overflow would fill your bilge. I would think you would need check valves on both the bilge line and the vent, unless you have them oriented where down is always out.

[mevirga]

Yes. Thanks Chexi. You helped me answer my own question.