We recently had our countertops changed, which involved disassembling our plumbing. After the reassembly by the plumber, we noticed water leaking from the air gap on the RO faucet. Upon investigation, we discovered that the black tube connecting the faucet to the drain adaptor was clogged with debris from the garbage disposal. I had to clean the black tube three times since the countertop installation.

I have doubts about the plumber's connection of the lines, but I'm unsure how to fix it myself. I would prefer to avoid calling another plumber for something I feel comfortable fixing on my own. Any assistance regarding this matter would be greatly appreciated.

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  • 1
    This isn't about the question you asked, but: the P-trap on the right looks like it's installed backwards. (The more curved and shorter arm should be connected on the outflow side, not inflow.) All the more reason to move the RO connection.
    – Kevin Reid
    Commented Jun 19, 2023 at 20:28

2 Answers 2


The way your drain is currently set up, the P-trap for the garbage disposal is too low. The disposal water sits there in the T where the RO drain is connected.

Remove the RO "T" and attach the P-trap to the black elbow of the disposal. That makes that connection correct.

Cut a section out of the sink tailpiece and add the T for the RO drain.

This puts it above the P-trap and no water will be sitting in the drain tube.


It does look like bad place for the RO drain.

Two options.

Install a L (90 dgr) in the drain with a vertical line going above the disposal outlet than install the RO outlet on top. - no cutting required

Second option, close the current setup and install the RO drain in the vertical line from the sink. Cut and insert a T .

  • Your second option will result in a fair bit of noise.
    – isherwood
    Commented Jun 19, 2023 at 21:02

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