Depends on your medium. But generally. Also don’t test the initial runoff that would contain any dried up salts. Personally though. In going on 5 grows I’ve only checked my runoff 3 times. All in the first grow. Processing overload is real. The less actions you take, the less potential for error. I only check my run off if I begin to notice an issue, that way I don’t try to correct non issues that would cause an issue. Of course this was my practice in soil. If I started in hydro/coco it would be different. Now I can see early warning signs before they matter though. So I still don’t monitor runoff in coco. The leaves tell me all I need to know.
Above is why we tell people to not give up ever. It really is an easy hobby. It’s only hard when you over think it or attempt commercial numbers.
Welcome Don ! I like to remove my plants from the tent and set on a homemade rack and slide a large glass casserole dish underneath to catch the runoff when watering or feeding.
I always let plants drip out before returning to tent. Also slick bottom dish easy to wipe and clean don’t contaminate next pH or PPM check. Just my thoughts good luck.
I hover over my plants, but I don’t do a lot of the things I see recommended. I’ve never tested my runoff. Mostly because I grow outdoors and it’s not something you can do there so it’s not something that needs to be done. Also, I’m not feeding my plants, I’m feeding my soil. Other than an occasionally tea (to boost the bacteria/microbe population), they get only Happy Frog dry amendments (indoors) or Alaska fish fertilizer(outdoors) at half strength.
If I were feeding my plants, I’d saturate the pot with the mixture. Normal watering that wouldn’t be necessary.
I use dry amendments so I water every couple of days or so and soak the pot at least once a week (water to runoff).