Plugging a 5/8” hole

[RWReefer]

Hey all. I’ve got a 5/8” hole in the RO/DI storage container for a mixing station I picked up that sits under the water feed shutoff valve. Having a time trying to figure out the best way to get it plugged up.

Any thoughts would be greatly appreciated.

Can’t find a bulkhead with cap. Compression seals all have stainless which I’m worried about leaching eventually. There’s got to be an appropriate solution that I’m missing.

Thank you.

 

[Peace River]

Some type of compression fitting would be better, but what about a rubber grommet or silicone plug?

 

[KrisReef]

Here is the fitting, put a blank in it.

https://www.avastmarine.com/products/1-4-bulkhead?gQT=1

 

[RWReefer]

Here is the fitting, put a blank in it.

https://www.avastmarine.com/products/1-4-bulkhead?gQT=1

Thank you!