Hey. I've grown the SLH before. Takes about 9 weeks 60-70 days, but, going by these days is just a guide.
You really are missing out on a lot of potential bud potency r even loss by not having one.
As going by the look of bud. Well. It really can't be.
One way to get an idea of how many clear you've got is to take close up pics with the flash. Anything that shines is clear.. using this will give you a better idea of what your Cloudy/clear ratios are.
Or ur phone. Pic off a bud or as steady as you can with the bud..zoom right in and let it focus. You should see something.
But, for the 8$ a phonescope/loop costs you really should get one.
Id start winding down on the feed in a few days and let it finish off. You'll also know if your fluid intake drops off dramatically its more than done. These are small things that will help you determine your harvest day.