I modified the flow on my Spec V and wanted to share it. I didn't see anyone else doing the same thing so hopefully this will be valuable to someone.
The default flow on the Spec V is too much for my beta. I had a sponge stuck on the nozzle for the better part of 7 months. The problem with the sponge is that it restricts too much flow. My beta liked the lack of current but I got a blue green algae outbreak and in general some water quality issues.
My solution was to crimp the rubber hose that attaches to the pump and put a zip tie on it. This has the benefit of being adjustable, and not harming the hose. I had to play with it a bit to get the right amount of flow. And if you go too far you have to cut it off and start over with a new zip tie. But it works incredibly well. Plus you get to toss out that sponge.
Here is a picture of how my tube looked once it was crimped.
Hopefully this helps folks going forward.