My suggestion is that you should dump those Alphacool 90s and get some Bitspower 90 adapters. Alphacool is pretty much garbage when it comes to anything with a rotary element. Only thing I'd trust from them fitting-wise would be anything without a rotary element to the fitting.
Personally had a catastrophic leak that got Mayhems Pastel Green all over the place a few weeks ago when I was rebuilding my loop. And it was because the male-to-male rotary I bought from them had a very large leak from the seals/o-rings that make up the rotary element of the fitting.
Save yourself from having a headache in the long run. I cheaped out, and I wasted ~$5 for a gigantic (albeit small fitting) piece of crap.
And yeah, looks like I wasn't the only one who had an awful run-in with those leaky pieces of crap: http://www.frozencpu.com/products/15701/ex-tub-1244/Alphacool_G14_90_Rotary_Fitting_Adapter_-_Deep_Black.html?tl=g30c101s1306