What to hold pH adjuster in for Bluelab pH controller?

[sativuhhh]

Finally getting my RWDC up and going and was setting up my bluelab ph controller and was curious what to keep the ph solution in for the pump. Should I just drill a little hole in the cap of the ph bottle and run the line in or is there some other better vessel to hold it for the pump?

 

[Listersmeghead]

You can buy little rubber corks that are shaped to fit in most bottles, they have holes in the top for syringes and tubes.
You can get them from wine/beer making places . Moonshine stills use similar I think.