No airlock activity

This is my 1st attempt at mead, followed this recipie with one alteration, I substituted limeade for lemonade concentrate (as limeade is inherently superior...). Its been ~24 H since I pitched the yeast and not seeing much int he way of signs of life, no bubbles, nothing at the airlock, theres's a puffy mass at the bottom of the betterbottle, but I'm unsure if that's some of the limeade solids falling out of suspension or if its yeast.

I'm thinking it either got too cold last night and killed the yeast, or the PH is out of wack potentially.

I've never used D47 before so not sure if its slow to start or something...
Planning on swinging by the local store to pick up a PH kit and more yeast...

ETA temp was high 50s when i tested it this morning so I have it sitting in the tub trying to get it up to 65-70

went do the local store, bought some stuff (more d47 and more nutrients and a heater thing to keep the temp up at night.) and threw it in and 3 hours late i got a bubble
So apparently something is alive in there its just moving super slow.

I have a feeling i probably got impatient and its going to explode tonight...