Azumarill Annoyance

OK guys, so I've been busy breeding Marills for this Azumarill I'm planning. It's a Sub/Belly Drum/Salac strategy, but there's a teeny problem. See, I need the HP to be even for the Berry to activate after a Sub and a Belly Drum. So I bred for a 30 IV in HP (along with a 31 in speed and attack) and threw in an EV spread like this:

Jolly/252 Atk/252 Spd/6 Def

I had reason to believe that the 30 HP IV would give an even number. And it did. But only at level 100. That's cool but I play way more level 50 battles than 100 so I was wondering how I can work out an HP IV that would give me an even number at level 50 AS WELL AS level 100. Any suggestions? Or is the EV spread a bit dodgy? I'm completely stumped... stupid Azumarill...

I don't know much about EVs at level 50 but shoddy can work for you as a way to instantly calculate stats at any level. You can just use trial and error and see what works.

PokeSav to the rescue.

I use PokeSav for things like this all the time- use 28 HP IVs, and no EV investment. That'll give it 124 HP at 50, and 238 at 100.

Is there any way he can add EVs to HP to get even HP at both levels? It'd be easier to add EVs than rebreed and retrain another Azumarill.

Thanks guys =) Very helpful. I'll try out what you suggested.