Just started flower...nitro def?

Looks like ph to me, checked it lately?

Can't afford a ph or ppm meter.

dig that. Can you just grab some of the test strips from WalSatan? They're not exact, but they'll let you know you're in proper range at least when you water.

I don't know your grow medium or feed, but I'll be honest, I never check ph either, and it's for only one reason. Every time I feed, I add 1/8th tsp/per gallon of Miracle Gro Bustin Blooms 15-30-15, or the WalSatan version called Garden Sense that is $3 cheaper, but a box of either is still less than $8. It adds a little bit of feed at that dose, but not much, just reduce your regular grow by a ml or so to compensate. The chelated salts keeps the soil ph in proper range.

Of course, if you're dead set on organics, or something of that nature, then this method isn't for you, but it's worked for me for decades, with multiple water sources in multiple spaces. Just make sure it's the 15-30-15 and not the All Purpose with is 28 for its N.

What type of water are you using?...tap?
How are you feeding that scrog?
Also maybe a tad cal mag
My two cents

Fox farm oceon forrest. Using batonicare veg transition and bloom plus the flower. Tap water has been ok so far so that's what I have been using. Maybe I need to pick up cal mag? I feed at every water. Maybe a flush is needed? Not sure. I gave them a Lil extra nitrogen last night. I'll be able to see tonight.

If it's a ph lockout feeding will only add to the problem. Depending on where you are, tap water sources can change. It's possible your supplier is pulling from a different reservoir right now, if you've never seen this issue before. You can check it with the cheap pool strips too. I'd spend money on the strips before I dropped money on cal mag.

Ditto that...spend no more money anywhere until you can save up for a good pen IMHO....
Gotta have the good water...

I use the cheapo yellow digital pen...it gives me a close enough range IMO.....like 21 bucks at hydro shop

Home Depot has Soil Test Kits that test NPK and PH. I use them in my Outside garden and they work great.
http://www.homedepot.com/p/Ferry-Morse-4...t-920/202819850

A wise man once told me the thing to remember about plant nutrition...... Less is usually more...

They were just hungry....looking much better.