What could have cause my slow start

I have a Pineapple Kush that sprouted in a rockwool cube and I placed it in a bubble bucket with Hydroton.
32 days after sprout the roots finally came out of the 6" net pot. This is when the plant actually started to grow. I had the lights on an 18/6 cycle through this time. Temp @ the highest was 88F for about 2 hrs 1 day and the lowest has been 64F. Humidity has been around 20%. Now its growing fast, 15 days later and the PK has the 4th set of nodes and the 5th in queue.

What could have caused it to "hibernate " for 32 days?

So no one knows what could have happened. The sprout didn't grow at all, not even new leafs for 32 days, Usually by 32 days the plant is filling my cabinet.

Some strains start slower than others, my recent slow start problem was pH, your pH in check?

Yeah, I keep it @ 5.8 in hydro. 5.5 was the lowest it got, I check every night before bed

Were you starving them (like most people here suggest to)? What was the ppm then and what is it now?

Some (most) RIU users like to starve their plants when they're young.

In hydro, pH being off is the #1 reason for slow or no growth. When the pH is off, nutrients are locked out and the plant can't use them.

I mean yeah, some stains are slower than others but 32 days with no growth? There is definitely a problem there.

And church haze-- so true. I just started aeroponic and was all afraid of burning them at first. Even tho the plants are just seedlings, the ppm in my res was still dropping. Which reminds me of something to tell the op-- if your water level is going down, bit your ppms are going up then your plant is locking out nutrients and not using them. Do you check your res temp?

I religiously keep the PH at 5.8, I check before bed every night. I did not feed them until I got the 3rd node showing, My tap water is always around 200ppm with the 24 rest period to allow the chlorine to evap. As for water temps, Its usually around 65-70. I use the frozen 1 ltr water bottle everyday about half way through the light cycle.
I did read at another forum that Pineapple Kush is notorious for these slow starts.