Seedlings barely growing

I started 1 AK-48 and 1 indica aurora 6 days ago and the plants are only about an inch/inch and a half tall. There is only one set of true leaves that are open and the second set is just barely starting to come in. There is just the faintest purple color to the tips on leaves of the IA. Other than that both the them look like they are a healthy green. It's almost like im imagining the purple tips but its there more so on the IA. Maybe just genetics? Also when the AK first sprouted the first fan leaves were super tiny and yellow but somehow it corrected and they turned out ok.

This is my first grow and I'm doing it inside of one of those PC grow boxes with 4 CFL lights. I know people have grown in these before and got a decent harvest so it must be something that I'm doing wrong. I got my potting soil from the local garden stores and I have not added any nutes. I got a basic pH testing kit where you open these little capsules, mix it with some soil and water and then shake it up. It turned blue which according to the test kit indicates that my soil is too alkaline?

I'm guessing the main things I need to do are puchase a pH tester to test my soil and also my water before I water. Any other suggestions are greatly appreciated.

lower nighttime temperatures sometimes cause purpling (purple is just a color, has nothing to do with potency, anyway) ... if your temps drop below 70 degrees, growth slows, accordingly ... also, avoid over-watering, allow the plants to dry between waterings ... do not feed, until the plants are two weeks old, and half-strength thereafter ... more damage is done, with overfeeding, than harm from under-feeding ... good luck :smokin:

Thanks so much for the input. I think my temperature has got to be above 70. I keep my AC on 74-76 and then I'm growing in a PC grow case with 4 CFLs so it has to be even warmer in there than in my apartment. I'll give it time and see what happens. :)