A few comments:
1) plumbing doesn’t increase the pressure your pump provides. The pump has a max flow. Things like smaller lines and elbows increase the head pressure, slowing the flow. That has the effect of decreasing the flow at an end point like your reactor, which decreases the pressure there. If you’re necking down plumbing or adding 90s to increase pressure inside the reactor, those measures will have the opposite effect. I agree with the note above that the reactor doesn’t need high pressure. It just needs enough flow to tumble the media, which isn’t much. If you overdo the flow, you’ll pulverize the carbon into fines, which could get into your tank.
2) the refugium looks like it’s sitting on a block that’s smaller than its base and focuses the weight of the tank on the bottom glass. That may be just a temporary setup for the picture but, before adding water, make sure the refugium is sitting on a sturdy base that is as big as or bigger than the tank bottom so the weight of the tank is spread out on its frame. Otherwise the bottom will likely break.
3) if space allows, I’d put the refugium a little higher to allow room for a vertical drop in the line returning water from the refugium to the sump. I’d also reduce all the elbows in the refugium drain line to the sump. Ideally you want water from the refugium to have a very simple drop into the sump. I’d also terminate that pipe just slightly below the water level in the sump. Having it run all the way to almost the sump bottom could create air lock — a pocket of air in the pipe that the drain flow can’t purge, causing the drain to back up.
4) consider putting multiple drains from the refugium to the sump. A single line like you show will inevitably get blocked by macroalgae or some other refugium inhabitant and the refugium will overflow. An overflow box inside the tank with a weir will help with that. The interior side of the Fiji Cube overflows would fit for an application like this. Or you can just build a box of egg crate and use some zip ties to attach it to the wet side of the refugium drain bulkhead. The idea is to stop any algae or critters from blocking the pipe.
This is all in addition to the good tips other responses provided, which are all good ideas.