Hi William,
Thanks very much to everyone on the site who has helped me so far and thanks in advance to everyone in this thread!
Ditto.
Okay, so the instructions are to master each jhana before progressing. The nun Khema has several jhana talks. feed://www.dharmaseed.org/feeds/teacher/334/ Sometimes she mentions just being in jhanas 1-3 for about 15 minutes (I don't really know how someone measures time in jhana... that's hard and I'm no jhana expert) before moving into new jhana. (I don't think this implies mastery; I have read that meditation masters look for several hours of stability before mastery is considered).
Am I better off trying to solidify it or moving forwards?
I'd use the word "suffusive" versus solidify. I would say, yes, get truly suffusive. Often I find for myself there's one point of discomfort that is dividing my attention, and thus jhana is not happening, though it can be close. For example, if the muscles under the ischial tuberosities (basically, the butt muscles) are feeling uneasy or the ankles are achey or the back has a discomfort... for me, this means my attention is divided and jhana is not occurring. That's okay. But it teaches me to make a sincere effort in the first few minutes of meditation, before the body is tired.
Regardess, it's a training. It takes time and patience, like playing piano, coding, driving, cooking, foreign language. So most important, to me, is sit down and get sincere right away: vitakkha, vicara.
When this is easy to do straight away and is suffusive, then move the mind to the pleasure (piti) there.
My question is, how long should I be attempting to replicate reaching first Jhanna and at what point should I move on to trying for second Jhanna?
When there is a suffusive and lasting first jhana, the mind will naturally move to focus on the piti that's arising. That's a good time to go into it.
Regardless, you can't really do anything wrong by investigating a weak concentration when the concentration is in jhana -- because they are positive mental trainings flooding the mind with pleasantness.
What can happen though is that without really getting a suffusive concentration state, one can start to embellish a lowly uncollected experience, a non-concentrated experience, or a not-quite concentrated experience, a non-jhana, and that's too bad because suffusive concentration is remarkable. When it happens it gives confidence to the practice and teaches large parts of the egoic brain to stand-down, to trust that it can let go into the practice.
This is when But even access (aka "neighborhood") meditation can get relaxing, alert and very refreshing.
]Better to do 15 minutes sincerely like this, than a bigger bit of time, I think.