Light brightness.

I use photone and set my light for 8Dli for the 1st few days then increase it to 10Dli for a week and keep increasing every week until I get the plant to take about 35/40dli. That is from my phone, its took me a while to find the sweet spot for my lights. It takes a few grows to figure out what the plants can and can't take at various stages of the grow.

To add onto clydegrows answer, photone is a great app when its calibrated, so even if its not setup correctly, it will be consistently wrong in the same way on the individual device so you can have a range to aim for, make notes on what works and then set that as the new par. It is not universal across all devices either as I tested this on 4 devices "mine and my friends all uncalibrated" and two of them were the same phone model, none of them where in the same range, all off by 50-100 some as much as 500 PPFD. You need a proper light meter to calibrate the app, but once done its a beauty. Or just use it as is on one device and note its not an accurate measurement but it will be consistent. Cheers,

If you have a smart phone download yourself a ppfd meter app, such as photone. That way you can measure the light in either ppfd, DLI, or lux and you will know how much light you are giving your plant. A seedling only wants around 150 ppfd.

Vivosun does not have a 1000 watt led lamp. Look at their official website, search for your model led and check the manual with all the specific information and instructions about your lamp. Here is the link: https://vivosun.com/Grow_Light-c3 Enjoy your grow!

1000W light, dam gone Nuclear. That's packing some serious power. Your diary says your using a 600w HID style light so that's confusing. So for a 1000W I would dim brightness to 30% and hang height of 25-30" that is if its a true 1000W light, some amazeon lights say 1000w but really they are only pulling 150W, you would be best to post a link of the light you are using. The manufacture will have some suggestions so you should 100% check the Manuel for some of this information If this was a typo and its a 100W led I'd bring it down to 25" no dim. We will not be notified of any reply in the questions part of the website, if you need to reach out with other information use your DM "direct mailbox" in the bottom right hand corner of the page. it looks like a little paper airplane icon. Best Of Luck!