after a few grows I use a omega meter not cheap , but it replaced about 9 cheep meters 10 years ago.
Of all the things I would buy for growing is a real expensive meter.
It must be stable ,repeatable,and last.
Note after lots of cheap meters I have bough the $300 buck meter was the cheepst and most accurate.:thumbsup: :thumbsup: :thumbsup:
your splinting frog hairs to get the most production.
when you play with mother nature, you want her always comming.