I would recommend watering it more often than every 5 days, but that depends on the type of lighting and other factors.
Promix mixed with Perlite 50/50 would have very little water holding ability...I use
Promix myself and I usually mix some composted manure in it to aid in water retention as well as supplying the micronutrients that
Promix doesn't have. I give mine between 1 and 1.5 gallons of water per day per plant, using 5 gallon buckets and
Promix. I love
Promix but cutting it with Perlite would be like growing it in straight gravel...it only gets water when it is actually watered since it doesn't retain water well during the in between periods. The plants look fairly healthy other than the wilting and stress. How big of a container are you using? I'm not familiar with the AN fertilizers, but
Promix and Perlite have no nutrients in them...I use 20-20-20 once a week and water daily.