[hylld4ff]

First grow, Northern Lights, soil in a 10gal fabric pot. The pot is on an AC Infinity self-watering base.
The plant is still in veg, it is in its 10th week. I intend to keep it in veg until week 12 because of travel arrangements (I didn't want to be away during flower).

The soil is a mix of Canna professional plus, perlite, worm-castings, charcoal, mycorrhiza.
I am using an two old tubs of General Hydroponics Biothrive liquid organic fertilizer.
When feeding, I take 3L (0.8 gal) of water, add 3-6ml of CalMag, 1ml of Biothrive Grow, and 1ml of Biothrive Bloom.
The packet instructions on the old tubs (they are +10 years old), is to add 0.35 Grow and 0.35 Bloom to 1L of water, so my mix is roughly in line with packet instructions. However, online I see that they now recommend 4ml to 11ml for that amount of water (perhaps the package instructions are outdated).

The plant was doing great until about the 7th week of veg. At this stage, I started introducing the self-watering base. Things went downhill after that with leaves turning yellow. My initial diagnosis was that the plant was getting overwatered with the addition of the self-watering base. I experimented with gradually removing the number of wick lines on the base, I went from 4 all the way down to 1. Due to the over-watering introduced by the base, I have been inconsistent with feeds since week 7 (drybacks to recover from overwatering).

Today I picked up cheap soil PH meter, and the readings indicate that I am slightly on the alkaline side, with a range of 6.5-7.1.

The symptoms are leaves turning pale and yellow, with some cases of brown spots. See pics (apologies for poor quality).
I am about to leave for two weeks, and will have to rely on the self-watering base (will be topped up by a friend every few days).
If I'm lucky, the plant can still go through flower when I return, but nevertheless, I want to figure out what went wrong and do better on the next grow.
Feedback greatly appreciated.

 

[GNick55]

i’d like to see the whole plant in normal lighting,.

 

[bushpusher]

I'd damn near guarantee its a case of overwatering. I had 6 clones in my cloning box and I decided I'd pot up the worst looking three into bigger pots. (I only had three larger pots). I did the deed with my usual mixture of coir, compost and good potting mix and duly watered them into their new home. I totally forgot that I'd thoroughly watered them only 12 hours previously and thoroughly watered them again!!! Within a cuppla of days they look just like yours do. Yellowing, distorted leaves with blackish brown spots and tips. Dying leaves. I've added several pics and you can clearly see the ones that I "oversoaked" and the ones that weren't potted up. All I've done to improve them is stick 'em out in the garden in the sunshine tilted on top of bricks to get better drainage. The soil feels better now, just moist and the plants are slowly improving. But it's gonna take a cuppla weeks & the dead and damaged leaves will never go back to "nice green" again. The first three images are the relatively dry ones but still mildly affected by moving to outdoors. The second lot of three are the really soaking wet ones. You can see the damage, especially on the last one which is very similar to yours?

 

[compostmike]

Overwatering may be part of it, but the feed rate is another big red flag. The current BioThrive light chart for late veg works out to about 6.7 ml Grow in 3 L; you’re using 1 ml Grow and adding Bloom. The pale older leaves and interveinal yellowing are consistent with the soil charge being spent and the plant running short. Replace those ten-year-old bottles, use fresh Grow at a conservative chart rate, and leave Bloom out until flower. Before traveling, find out how long one full base lasts instead of having it topped up automatically.

 

[hylld4ff]

the BioThrive series has changed since the batch I bought, and I realized that I was citing (and have been feeding) seedling / adolescent plant levels. for mature plants like mine I should be feeding 15ml grow per 10l water, and during flower it's 10ml grow + 10ml bloom (yes, the old recipe instructs you to mix bloom and grow during seedling and flower phases).

thank you for the information, it's very good to know that I shouldn't expect the yellowing to turn back to green, and the new growth has a healthy green color, so i'm confident that the plant will do alright if the self watering base serves its purpose during my absence.

if the plant is still showing signs of overwatering when I return, should I delay the transition into flower until it's looking healthier?

 

[Ninjadogma]

Looks like poor root oxygen. A little tricky to gage with a big 10 gal pot but you want that pot to drop about 25% of its weight in between waterings.

 

[Bongripsaplenty]

Looks like nute deficiency. Those wick bases can hold maybe a 7 gallon pot, no way its feeding a 10 gallon properly.

 

[Glomus]

Definitely a root oxygen issue, do you know your temp and VPD? I'd bet the soil isn't built for proper drainage. That is a common error. More perlite next time. But probably over watered from auto watering setup.

 

[bushpusher]

And the correct answer to my problem above is!!! (LOL) - I just left them out in the breeze on bright, winter cloudless sunshine days (Yes that's winter where I live, 40F to 72F. Unfortunately, summer is like Death Valley but you're still alive!). I stopped watering entirely and also covered the top of pots with plywood rounds so any rainwater could not get into the soil. Left them like that for two weeks to let the soil dry out completely and bingo they're all recovering, slowly but improving, all returning to green leaves and looking like living plants again! They are transpiring again. I reckon they won't be as good as undamaged plants but it's better then losing them entirely. Maybe this the answer to the OP's problem too?

 

[hylld4ff]

yeah, confirmed overwatering problem. started improving as soon as I let the soil dry out and switched to handwatering

 

[Ninjadogma]

yeah, confirmed overwatering problem. started improving as soon as I let the soil dry out and switched to handwatering

I use empty water bottles with holes poked in the bottom... Put a couple bottles down on top of the soil, fill em up and move on to the next plant and do the same so you get a nice slow watering without having to sit there like an idiot with the can in your hand working on one plant for half an hour.
Glad to hear your grow got back on track. It's been a month, you got fresh pics?