any idea how i can tell when their ready? to harvest
Absolutely... there is only one method that works with any variety at any time. You must look at the trichomes on the buds. Just from the pictures, and only making an educated guess, I would say you have at least two and maybe three more weeks. But see my explanation below, as harvest timing is not an exact science.
So how do you look at the trichomes to decide when things are ready to harvest?
First, you need a jewelers loupe... and a light is helpful. Here is a cheap one that I use for looking:
SE MJ362242L 20X and 40X Dual Power Illuminated Jewelers Loupe - Amazon
After you get the loupe, you use it to examine the trichomes on the buds. There are basically three states - clear, milky, and amber. The exact colors will vary with the variety - but everyone has the clear state.
When the trichomes are clear - you have not yet reached the peak of THC production.
When the trichomes are milky - you are at peak.
When the trichomes turn amber - they are past their prime.
You will never get the whole plant to turn at once. So you look at various parts of the plant and average the amounts of clear, milky, and amber trichomes.
And there is a LOT of personal preference in harvest timing. If you harvest early (when most trichomes are clear), you will get more of a mind buzz. If you harvest late (when most of the trichomes have turned amber) then you will get more of a body buzz.
I say "more of" because the type of high is predominantly determined by the plant type (indica for body buzz and sativa for mind buzz). So if you harvest a sativa late... it is a little like harvesting an indica early. And harvesting a sativa early produces an incredible mind buzz - too much for most.... perfect for active stoners. Harvesting an indica late will produce couch-lock... which is what many people desire for medicinal / pain management.
The best thing is to get a loupe, start looking and thinking about percentages, then harvest a bit when the trichomes are clear. Harvest some more when they are mostly milky. And then harvest the final bit after more than 50% have turned amber (or dark). If you keep the weed segregated - it will help to teach you the difference in high... it should be very apparent. You don't have to harvest a lot during this experiment - harvesting too early will reduce yield. So just take a bud or two and quick dry them to get an idea of how the weed will taste and the type of buzz.