Hello everyone so I am soon going to purchase an RODI system for underneath my bathroom sink and before I get it I want to know where I should drill the hole for the drain line on the filter. I know putting it straight into the sink is an option but I’d rather have it look tidier. Some people have said install it above the taller thread in the left side of the image but I don’t think this will be possible as above it is then metal which I don’t think I should be drilling with my little plumbing experience. Other people have said do it just below the second thread but in response to that it has been said that’s a bad idea as it will allow gases to leak through the trap. Anyone has any ideas lmk. Thanks!