So I am currently growing 2 WW auto flowers in a homemade indoor grow tent. they’re being grown using the pot for pot grow kit. the smaller plant(1.5 gallon pot) is in its 7th week of flower and the bigger(2 gal pot for pot) is in its 5th week of flower. The plants are watered every 3 days with a cycle of ph water and nutrient water. the nutrients we’ve been using is the fox farm line, grow big, big bloom, and tiger bloom. using a gallon sprayer we’ve been putting about 1 1/2 tbsp of tiger bloom and 2 1/2 -3 tbsp of big bloom. I stopped using grow big once the plants started to flower. My Ph tester broke not too long into my grow so I’ve been using the general hydroponics ph testing kit with the droppers. the plants started to yellow first, then brown, then curl up about 2 weeks into flower. any ideas on what’s wrong?
Could be a PH nutrient problem causing a lockout. Let me tag some more experienced growers @Covertgrower @CoyoteCody @Myfriendis410
Ph could have definitely locked out some nutes, i would get a new meter asap.
PH shocked. Nutrient water is way way down in most cases below 5.8 and real bad things happen during flower. This week, I PHd my tap water, after it sets a couple days, to 6.5. I added tiger bloom 4 teaspoon full strength to a gallon and the PH came back below 5.0 
if I had used it 6 weeks into flowering like where I am and it would be me here probably asking what is going on. You did come to the right place, you can use the search bar up top to look for related info. Welcome to the group.
Welcome. Solid advice here.
thank you so much! what ph meter do you use? or do you know any cheap good ones i could get?
I use the Blue Lab ph pen for soil, love it.
yea i’ve heard that’s a good one but it’s a little pricey. do you know any others that are less?
No I don’t sorry, but I will tell you that I, like probably most people on here start out buying very inexpensive tools that really don’t work at all. Buy the best or expect to buy it again and again until you do buy the best,lol.
Look for Vivosun on Amazon, they have a special on a ph and a tds (total dissolved solids, counts ppm) pen meter for like 20$. It is the low end quality for sure and better are available and worth the investment as sparkler mentioned.
Look at the Apera PH-20. Less than $50 and works well. Company support is great as well. I have it now as a backup since I purchased one of their new fancy models that does it all.
I use this vivosun set. If u rinse them good after every use and store them with the cap on dry they work great. Mine dont get dropped or banged around tho. U will need to get calibration fluids for it tho to keep them calibrated further down the line as they only send a set to get u started to make sure it is calibrated to ur liking. So far i have not had any ph issues but do plan on getting an apera that does both together for the next grow. Happy growing hope u get the problem resolved
Correcting water pH is the last thing you should do. If you adjust PH before adding nutes to the water the PH is going to be way off after adding nutes.
Yeah I’ve never had that issue before. I didn’t get as much late flowering production before because I didn’t know about lower ph requirements during flowering. Decades since I’ve done any indoors for me, it’s all changed for the best.
So it looks/sounds like you locked yourself out of potassium/phosphorus. Based on what you said, it sounds like maybe this occurred.
Nitrate abundance in your soil caused the ph to rise and locked out the potassium/phosphorus.
So regularly, the ph of your substrate and the ph of your nutrient solution are independent in the sense that, your substrate’s ph is derived from organic material changes (solids) and molecular exchanges resulting from nutrient uptake. The process your plant uses to uptake nitrates raises your soil ph. it can begin to alter your substrate ph to levels where the plant starves or gets flushed. Because of how dark green your other leaves are… and the timing on when your damage first appeared… you most likely had nitrogen accumulating and as your plant absorbed it, the soil ph changed. It raised your soil ph and locked you out of potassium/phosphorus at the exact time when your plant was craving them, which is why they started to show symptoms.
It doesn’t mean the ph of any of your nutrient solutions are necessarily off btw, you can def achieve this lockout just thru excess nutes
hey guys so i flushed my plants about 4 days ago(look at my other topic) and this is what my plants look like now. any advice on harvesting or what i should go to help spread of leaves?
Looks like you still have lots of white pistils.
Have you measured your pH and TDS/PPM?
I would think you need to get back on a feeding schedule and continue with some Cal-Mag.
You may also be able to harvest the upper buds if you think they are ready. A Steger harvest will give the lower buds some more time to mature while drying the ones which are more advanced. Check the trichomes for cloudy - amber color.