Help identifying problems with plants

These plants have some yellowing bottom leaves and several tips are turning brown. Some brown spots on some of the bigger leaves too.

At day 27, is this signs of over fertilization? Or under fertilization?

they are being grown in shultz potting soil plus, it has 0.08-0.12-0.08 time release nutes. 1/4 strength nutes (20-20-20) were added a couple times seperated by 1 clean watering.

2 seperate plants, both same symptoms.

any help solving this is appreciated.

those plants look pretty healthy, a few of the lower leaves will turn yellow and die off naturally, this is normal. browning on the tips may be the start of nute burn though. if you are using soil with time-released nutes that might be your problem. you have to be very careful not to overwater when using soil with time-released nutes.

It looks like a little much, let the feeding seep in before you keep adding more, let the fresh water wash this out before you go adding more. Are your plants getting micro nutrients?

The soil has micronutrients. The Fertilizer I got has boron zinc copper magnesium manganese iron

that's on top of the usual three. This is standard fert I think. I've used very little.

deliott said:

The soil has micronutrients. The Fertilizer I got has boron zinc copper magnesium manganese iron

that's on top of the usual three. This is standard fert I think. I've used very little.

Click to expand...

They getting any calcium? if your using any lime than you are. They do look like nice little plants overall.

Yeah there is lime and ph is 6.5

full flush yesterday to make sure about overfert. This morning they grew a lot. Will see how it goes as they dry up.

i wouldn't be too worried about nute burn until you see it move up the plant. just go very easy on ferts from now on

well i've switched the setup to a 4x4x7 tent with ventilation and 600w mh with glass shielded reflector. moved the humidifier in there with the fan and the whole thing is stable at approx 80 degrees, 50% humidity and everything seems to be going well. the growth has boomed and is going a lot faster, but the problem is not going away.

the bottom leaves turn somewhat yellow compared to the top of the plant, which is really obvious in the picture below.

I've given them a small amount of 1/4 strength 20-20-20 ferts between 2 clean water.

after the ferts, overnight they grew quite a bit. the top of the one is quite large now, but the leaves at the bottom are showing more signs of some yellowing at the tips and some yellowing of the leaves. still only the bottom 2 sets of leaves only.

during the last week of just normal water (twice), the plants didn't really grow that much.