Sucking sound

[Scote]

I start to hear a sucking sound after every layer. My guess is the vat is not tight with the lcd screen.

Any tip how to solver that? or is it a big concern?

[IllDante]

It's more likely the model sticking to the FEP and creating a suction effect.

Is your model hollowed and "sealing" to the FEP? (Is it round, or are the layers printed in a completely "flat" effect?). If so, maybe add some drain holes on your print to ensure air and resin can escape and potentially cause less harm to the FEP layer.