Reverse Osmosis about to drive me CRAZY! e location

[sixgun95]

Just had our existing 5 stage reverse osmosis system reinstalled and its about to drive us crazy. You use the equivlant of 1 pot of water from the spigot and then the "loud draining" noise occurs for about 45 min - 1 hr. Like I said this is an existing system, we had a leak, plumber slightly changed the pipes, now this. I emptied the tank, shut off the water and ball cock to the holding tank, psi is at 8. I vaguely recall an issue with our old system 8 yrs ago where it was making a loud draining noise and I think the plumber moved or did something with the drain line in the horizontal pipe. As you can see from the old plumbing pic (right pic with destroyed cabinet bottom) the drain line location moved farther away from the down spout. Thoughts?

 

[sixgun95]

Nobody? Is it because the drainline, the red tube going to the horizonal pipe, is farther away from the vertical pipe now? Moving the red tube closer to the vertical pipe fix the noise?