Hi Willy, sounds like the o-ring on the drain pipe isnt sealing. First, remove the pipe from the overflow box to inspect the o-ring for cracking, nicks, tears, etc and reinstall if everything is ok. What you can also do is swap the o-rings with the upper middle or left pipe to see if it now leaks in other spots. Reinstall everything and add a couple of inches of water into the overflow box to check for leaks. Please do not use plumbers tape to try and seal it.
If it continues to leak, send me an email at
chanht@redseafish.com