2 pumps to 1 may have given you more flow in numbers, but the reality in your tank (Hello, turbulence!) may be different.
Being down to only one flow source (single point) can actually decrease overall flow due to the increase in dead zones - or areas that are somehow physically obscured from the "line of sight" of that one pump, thus now depending on "reflected" flow which is always going to be less powerful than the originating flow. Maybe half or less depending on the case. If you put any of that additional 30 lbs of live rock into the tank, you may have contributed to this effect. Depends a lot on the layout of the tank, placement of the pumps, and even what kind of pumps, but something to seriously consider IMO. (Some rules of thumb: More rock = less flow. Open rock structure is better than otherwise. Structures built away from the tank walls are better than those that touch them.)
Mine is a different scenario from yours, but I'll give you an example of how big a difference a small (to you or me) change in flow can make. I once re-glued a baseball-sized birdsnest coral back onto it's mount facing the wrong way after accidentally snapping it off at it's base during cleaning. It was an accident in the first place as the colony was pretty uniform, with only a slight lean to delineate "front" from "back" and the tank was cloudy from cleaning - I just couldn't tell....not really even when the water cleared. (And I was a newb.) Anyway, after remounting, its lean was now in reverse of how it had grown in, and as I came to discover it was now leaning right into a "flow shadow" of a big rock that was up closer to the pump on the side wall. Leaning the original way it was clear of the "shadow" and getting nice flow all the time - it must've been just on the edge of that dead spot the whole time though. That birdsnest was 100% dead 24hrs later when I got back from work.
I would do your best to try and recall how the flow was for each coral before changing pumps and see if you can find any places that used to be high flow that now may not be - really any place there is a big difference in the before and after. The good thing if you find this to be the case is that it's an easy fix.
Anyway, just some thoughts.
-Matt
