Sick Plant, Yellow leaves, Brown Spots

[NinjaDan]

Hi guys

Im having some problems with my plants, the first one was grown from seed, its probably about a month old now, it had a rough start its first set of proper leaves browned and died off, but the second set was half grown, finished and the plant recovered. It went well for a while but in the last week both its bottom sets of leaves went soft and yellow then got brown spots and turned all crispy. Now im worried because the next set of leaves have also started to get brown/grey spots, this set however has not turned yellow. The plant is also not as green as it used to be and has slowed down its growing and done almost nothing in the last week

The second plant was from a clone that had already grown roots before it was given to me, its also about a month old and has grown significantly more than the first plant, however various leaves on it get brown spots shrivel up and fall off, while others seem to grow green and have no problems

I also have some new seedlings from some bag seed that appear to be doing fine, they are 5 days old and while they only have a few leaves the leaves themselves are as big as my much older plant, they where grown the same way as the first seed but for some reason did not have the same problems as my first seed

Some details,

The plants are under about 150watts of cfls, mostly blue spectrum, lights are about 6 inches away from plants

Plants are in soil, that has no nutrients, its mixed with about 1/4 perlite, i also had some fungus gnats so ive covered the surface in sand, this seems to have drastically reduced their population, but it seems impossible to get them all

Temperature 66-76 depending on night/day

light Cycle 20/4

Ph, Water going in is about 6.5, runoff is about 6.8 i try to let it dry out before watering to control the fungus gnats so hopefully there is no overwatering

I fed both plants a really weak solution (1/4 stength or less) of miracle grow and seasol (seaweed solution) a little while back, but then i flushed them because not too long after i had problems and panicked So aside from that they have recieived very little nutrients.

Ive taken a whole bunch of pics so hopefully somebody can help me out if you need any more info

 

[CMoon]

from the pics buddy shes deffinatly lacking in nutriants......if you say theyve already flushed id give them some desant veg ferts.......be careful with MG it carrys a lot of nitrogen and you dont want to burn it until its harvested.......for gnats i find sticky fly traps go a long way in preventing the flys from laying there offspring but theres chemical solutions available like gnattoff you can flush with, that can prevent the larve getting out of hand

bests cmoon

 

[NinjaDan]

Hey guys

Still having problems, i fed them both a weak solution of an organic fertiliser and i sprayed the leaves with about 2% epsom salts. The smaller plant seems to have perked up but my bigger plant still has problems, each day when i look at it more leaves have tiny brown spots on the stem of the leaf, these grow and connect in the middle of the leaf, and then eventually grow to the entire leaf, it turns crispy and can be pulled of really easy. This takes about 24-48 hours to happen.

Unfortunately i lent my camera to a friend, i have another but its a piece of junk and cant seem to focus on anything but the dirt behind my plants, so the pictures are pretty bad but will give you an idea

I would really like some advice on what i can do to fix this, and whats causing it, i cant find any similar pictures in any of the sick plant threads.

 

[African herbman]

I would say they don't like the PH much. Some like it lower, some higher.
I am no pro but I've had those same symptoms from ph issues.

Maybe 6.8 is too high a ph for your plants. Try get it a little lower and see how they react.

Hope they come right.
Ah

 

[demasoni]

I am having this exact same problem same # sets of leaves same stage growth with afghani kush. mine look just like his first two pictured plants. only difference is my first true set of leaves started with just one, then a couple. small brown spots/speckles near the stem, then worked its way upward to the 2nd and third sets of leaves. Yellowing came after the spots. the largest/oldest "fan" leaves have yellowed over completely/died, the rest appear stunted, yellowish, with teh leaves edges curling up like mag def, dwarfed off color growth like a zinc def.
150w flouro full spectrum about 5 inches under (isnt uncomfortable to wrist at plant level under lamp) ~71f avg..,
LC's soilless mix, 1blood,2bone,1/2tbs/gal soil of woodash. (without woodash that mixtures runoff was testing ~5.5 lower plus it didnt have K source yet. I remixed accordingly. The peat used in the first batch also smelled soured/mildew so I used fresh peat and transplanted to this fresh mix approx 36 hrs ago. Prior to the transplant PH readings were done with test strips with minimum 6.0 reading, and the soil beeing around 5.0 there was plenty room for error...after transplant Pen was used)
PH water going in 7.5
PH soil runoff ~6.5
I got that reading about 14 hours ago, before that the ph could have still been around 6.5 for another 12 hrs or so. Since then it might have improved if so Its BARELY noticeable. it seemed like the newest leaves at second internode had flattened out edges uncurled and greened up a bit a little after that last PH check. This morning the seem drawn up again like mag def with the veins closer together and ridged up, edges curlin up slightly and the richness of green going away. Does it just need more recovery time? I'm lost

 

[Hydro-Soil]

1) Figure out whether you're going to use nutes in a non-nuted soil or nutes to add to whatever manure, compost etc is in the soil you use.

2) Look around the boards for people that have posted their soil growing style and look for someone that has the type of environment and plants you're looking for.

3) Get those nutes and follow what they do as exactly as possible. Keep notes so that when you have issues, you can tell people exactly what you've done.

Personally I read the boards on OG and CW for over 6 months before I decided on a nute strategy. I looked for the most successful, easy to follow method with the fewest amount of issues posted by people. As a result I've had so few problems it's been ridiculous and the quality of the meds is fabulous.

Lucas formula, whether it's soil or hydro it is worth your time to find a source for the nutes. Lots of people use General Hydroponics FloraNova nutes to grow in their garden so it's not a big deal to order some online.