Grand daddy purp- Leaves curling up

Hey I was wondering if anyone could help me. I just started 3 GDP feminized. The leaf tips are starting to curl up. I hit em with 25% fert. One has yellowing veins too. I've been watering every 2 to 3 days. The temp is a consistent 71F and at about 45% humidity. I've tried all I can to get it up beyond 50% but my humidifier isn't doing the trick. If you could let me know what u guys think that would be great. Thanks again. Once I figure out to post a pic on this mobile site I will sorry thanks again.

Yahrp pics would be useful, how many sets of leaves on them ie how old are they, what soil and what size pot? It could be nute burn if they are very young and if there was food in the soil.

The standard procedure for this and most other plant problems is to flush the pots and leave it a few days.

What is the pH and strength of your feed water?

What is your grow medium?

Im using Fox Farm Ocean forest. The PH seems to be almost 8. i need a better PH meter. Here are some Pics

Ocean forest is to "hot" for young seedlings, try fox farms happy frog or light warrior.

I have grown white widow twice with fox farm ocean forest and gave them ferts and never had a problem.