Run d20 or hard 10.  No reason to ever run 25

They are the same rewards?

L20 Dungeons are the very best DD points and silver return per energy spent, which is why end-game players use L20 for Fusion Tourneys.

L25 Dungeons drop the best gear possible from Normal mode, but they were never a good place to grind because the extra 2 nrg per run adds up. 

L24 Dungeons offer the best balance of gear per energy spent from Normal mode., but if you are after the best gear possible, then it is time to climb Hard Mode.  Any level of Hard Mode will be better than grinding L25 Normal. 

So, my answer is slightly different than Trips' answer, but L25 is still the wrong place to grind.

L20 for points & silver

L24 for best gear if you can't breach Hard mode yet

The highest level of Hard Mode you can grind if the best gear possible is what you are after.

I am not sure you have the Roster Depth to climb Hard mode all the way to L10, but you should be able to climb a bit of the way with Mithrala, Artak, Champfort, Rathalos, Nekmo, Geomancer, Ghostborn, Demytha...

Make sure to have at least one AoE Dec Atk toon as well as Mithrala to cleanse as you climb.

I'm too lazy to offer more help than a 1-liner 😀

Seconding what Trips said. Run 20 or Hard 10. Hell, if you're set on running 25 and can't run Hard 10, run any Hard 1-10. All cost the same energy but every Hard version has better drops. 

Also, when Hard Dragon released, my Dragon 25 Team was able to do Hard 5 without any problem, so you can too if not 10