Can i stick to measure only the EC of the water for my plants

Can i stick to measure only the EC of the water because i don't want to spend too much money on this equipment

Im growing in an indoors closet using DWC system...So does different strains needs different EC level each week?

How can I know which strains need what EC level?

Most hydro nutes are based around mj even thow they won't say it. So there ec/ppm chart is pretty close if not right. Ec changes weekly so there is no set ec to say exactly where you can stay every week. In dwc PH is very important. So you will need a way to test that. But if you don't want to spend the money on a meter go to the hydro store pick up the GH ph kit. Comes with a bottle of up and down also the drop test kit. Costs about 15 bucks.