[Bird of Hermes]

Oh yeah they got me good took out half my grow im hitting my last two ladies with big time exterminator and green cleaner. After that im shutting down and heat treating and bleaching the room.

Might have just been some nute lockout of some kind they look somewhat happy in that pic. Unless growth completely stalls for weeks at a time id personally keep em going if you got the space to and see if it turns around. Good luck man

[Bird of Hermes]

Damn sorry lol forgot to say yeah just like 1 tsp a gallon of epsom salts. Normally cannabis wants more cal then mag like around a 3-1 ratio but some strains get mg hungry. If a feeding or two of the added mg helps then there will be your answer.

Mg defs respond well to foliar application so you can try that for a little while and see what happens.

[TanzanianMagic]

Originally Posted by colo720

Hi, thanks for input. .2 EC is only 140ppm , almost no nutrients, as my tap water is around 100ppm. right now they're getting 600ppm, with the feed schedule recommended by H&G for week 2 of flower.

The 0.2 EC of high P/K nutrients is on top of your water's EC - 140ppm plus 100ppm or 240, just over 1/3 of what you're feeding them now.

The purpose is to flush excess nutrients out of the soil, in case they are locking out nutrients. At the same time the Phosphorus is going to stimulate (very rapid) new root creation so the plant can take up more nutrients.

I looked at images of magnesium deficiencies, and it looks like its the fan leaves that show yellowing damage at the edges. the fan leaves on my plants have no discoloration - they are solid green. the light green yellowing is appearing at the center of new growth.

And they are showing classic magnesium deficiency/lockout. Here's why.

Magnesium deficiency moves up from the middle leaves of the plant. The oldest leaves are in the most advanced stage.

You can see the lower leaf with the crispy edges.

The newer leaves are a deep green, with an almost blueish hue. That is classical for early or mild magnesium deficiency. The edges of the newer leaves are already affected.

I'll flush again at 140ppm, with some phosphorus and potassium. I have shooting powder (0-9-20). But basically to flush at 140ppm I would add just a touch of shooting powder to the tap water. Does this sound right?

It sounds excellent to me at 240ppm (100ppm tapwater plus 140ppm Shooting Powder). You should always let the solution sit next to the plants for at least an hour so there is no temperature shock to the roots. It's more important that they're the same temperature, than that they're any specific right temperature.

Just flush the plant with that, and let it recover for a couple of days. You should also spray it with a solution of epsom salt (MgSO4).

[colo720]

Hi all, thanks for all your input. With your help I believe the original problem has been solved. This post is a conclusion to help anyone who may experience similar problems. (I also have a new question regarding the final picture of damage leaves)

Corrections for future grows:
1. add perlite to coco (don't grow in 100% coco)
2. carefully monitor coco, and only water when pot begins to dry out
3. I realize this is a given to most folks, but not to a coco newbie, despite years experience in 6" rockwool.

It appears the mom's are better - are no longer duds. over half the veg plants are better (and the other half on the fence), and the girls in flower are flowering, see pictures below.

1. Moms (pic 1): pure coco in 1gal smart pots. status: recovered. achieved by not watering daily. I allowed the pots to dry out for a few days before watering again, and at that point I flushed and I've been running weak nutrient solution 400ppm since. after an 18 hour light cycle they start to get dry, I'm watering just 1/day.

2. Veg plants (pic 2): same

3. Flower plants (picture 3): same - but these still look stunted. the pistols look good and I hope they'll pack on some weight.

4. new question: picture 4: weird discolored leaves - can't find any match on chart of deficiency's (pic 5). this came off of an auto white widow, wk 3 of flower. some of its sisters have the same issue. any ideas?

[Bird of Hermes]

Glad to hear you have at least some plants recovering im guessing it was overwatering from what you are saying? Coco can retain moisture pretty well so that would make sense. Pics didnt load maybe retry to post or try to describe the leaves as best you can.

[colo720]

Here are the 5 pictures that were intended to go with my last post:

1. moms
2. veg
3. flower
4. discolored
5. chart

[TanzanianMagic]

Originally Posted by colo720

Hi all, thanks for all your input. With your help I believe the original problem has been solved. This post is a conclusion to help anyone who may experience similar problems. (I also have a new question regarding the final picture of damage leaves)

Corrections for future grows:
1. add perlite to coco (don't grow in 100% coco)

Personally when I grow in coco, I prefer coco only with a perlite or grow rock drainage layer.

With coco only you need to water less, say every other day. However that depends on your environment, RH, temperature, etc. You can check out what you can get away with by not watering/feeding a couple of days and see what happens and when.