as this is your first grow, you can get away with anything you want to get by. but i think you might want to go thru the grow bible and see what it says about watering. when i first started 4 grows ago i was using and still use supersoil. i was told that i didn’t need a ppm meter because i didn’t have to check run off. but i was using well water that ran thru a brita pitcher water filter for the first two and just well water for the next two. 5 weeks into flower my leaves started turning yellow. and it got worse when i didn’t use the filter. on my last grow i had two tents one about a month ahead of the other. if this is going to be a “one-shot” and you are not going to grow again then you don’t need a ppm meter. if you are going to be serious about growing then you need both a ph meter and a ppm meter (TDS). i now use RO water and i’m trying to save my plants in the second half of my grow. the first half of my grow the plants did not get thru flowering and all the leaves turned yellow. i have now deduced that i had nutrient lock out on my first half after i bought a ppm meter and started checking run off for both ph and ppm. i had 7.4ph on the runoff and 2800 ppm. the runoff needs to be 6.7 or less or the plant will not take the nutes. yes, i still got pot from the first half, but not great pot. i am hoping to get the ph straightened out for the second half of the grow. the ph for runoff is around 6.6ph and plants are doing a lot better. no matter if you use RO water or not, the soil builds up salts that need to be washed away. that is why most suggest to water to 20% runoff so that you can get rid of the salts. i am watering now at 5.5ph trying to get the runoff back under 6.5ph and it is taking me 4 or 5 waterings and it still is a battle i’m fighting trying to get the second half of the grow to finish properly.
start at line 824 and look at the pics of the first half and read what i went thru trying to finally get this stuff figured out. but this is why i questioned you early in your thread about your watering schedule and practices.