Flowering plants with lime / yellow leaves

My first grow. Made mistakes. My plants are flowering but leaves turn lime green, then yellow, then after a week or more fall off. It started at the bottom, then working its way up. I have 3 plants in the tent and all are affected to varying degrees. I thought nitrogen deficiency but I feed nutrients.

Details: Bergman’s autoflower, 2x2x5 indoor tent, 3 gallon smart pots with coco coir, feeding hydroponics trio + calimagic (attached the feeding schedule and on week 5), LED 600W, two 4 inch inline fans - one for intake at the bottom, one at the top with carbon filter for exhaust, two clip on fans on low not directly blowing on plants, light schedule 18/6, alternating plain ph water and nutrients, nutrients going in ph is between 5.5 and 6.5 and ppm around 650 to 750, measured runoff usually between 5.5 to 6.5, but had to correct it once due to acidity > 5.5, haven’t measured ppm on runoff, daytime temp 78 to 83, night time 70 to 73

Thank you in advance for any help you can provide

This is a 100x difference. Need a more accurate reading. What are you reading with? Ph strips do fine for pools but this game needs a little more accuracy. If you’re hitting 6.5 you’re locking out most of your nutes.


This is also something you should check. Too many Ppms will also lock out nutrients.


Thank you for your response! I had read somewhere to vary the ph within the correct range to capture all the different nutrients but looking at this chart I can see why that’s not a great idea for a ph greater than 6.1.

I started out using ph strips but I second guessed myself too much trying to judge the color. So I bought a digital pen mid range in cost. It came with a few calibration solution packets that I didn’t use because I ordered bottles of calibration fluid. It calibrated perfectly with the 4.0 solution but read 6.8 with the 7.0 solution. So I adjusted for that on the high end. After reading your suggestion I dug the cal packets out of the closet that came with the pen and noticed the mid range packet was 6.8 not 7, so I guess the pen “corrected” the calibration to 6.8 thinking I was using their cal fluid ?

Next time I water, I’ll calibrate with their 6.8 fluid first, keep the ph lower and check the ppm on runoff instead of just checking before the feed.

Yeah, you must use the packets for those meters because they calibrate to 4.01 and 6.86. Make sure to use distilled water and do a two point calibration. 6.86 first then the 4.01. You can skip the 9.18 if it came with that

Made the tap water mistake early in the grow. Ppm with nutrients + tap = 875. Switched to distilled and total ppm was much lower and didn’t have to use so much ph down.

I hope that fixes the problem and I didn’t wait too late to ask for help.

Thanks again!

I meant distilled for the calibration solution. I used distilled for watering plants and it was leaching nutrients from the plant. I just use tap water with the chlorine gassed off.

I will definitely use distilled for the calibration solution.

Maybe using distilled to water and feed is a problem too?

If I gas the chlorine off my tap water will it lower the ppm?

No it won’t. Not anything noticeable at least. If you want to start with 0 ppm (or real close to it) go with reverse osmosis water. But with RO water you’ll want to be sure you’re adding in calmag.

1 Like

Got it, thanks!

1 Like