Why do my sativas always end up like this?

[TripsRabbit]

I follow GH flora series instructions on the bottle. I have no problems with indica phenos but my sativas always end up with problems.

What do you give less or/and more of for sativas?

And here is another plant fed with the same water.

 

[TripsRabbit]

I think it's excess P and K causing a nutrient lockout of magnesium . I'm growing in straight coco, pH is between 5.8 and 6.
Leaves tacoing, burnt tips, all the signs of an excess.

 

[Aqua Man]

They the same height bro?

How often are ya watering?

I think your better off sticking to a transition ratio personally.

Kinda looks like K deficiency and some excess Ca maybe.

 

[Aqua Man]

Sativa also appreciates a higher humidity so it could be water stress related also.

Just tossing out some ideas.

 

[TripsRabbit]

Sativa also appreciates a higher humidity so it could be water stress related also.

Just tossing out some ideas.

I water once to 3 times a day. I may or may not have let it dry out too much a few times. But even if I auto water my sativas end up looking like this on the flowering feed schedule.

 

[Aqua Man]

You giving full call mag through flower?

I'd cut back by 50% if so after stretch. Keep the humidity a bit higher with sativa also.

 

[TripsRabbit]

You giving full call mag through flower?

I'd cut back by 50% if so after stretch. Keep the humidity a bit higher with sativa also.

Yes full tsp per gallon of calmag till flush. You think that too much cal is locking out mag?

 

[BoostNBuds]

Yes full tsp per gallon of calmag till flush. You think that too much cal is locking out mag?

I believe it was stated that excess P and K can cause the lockout issue. If this always happens to your sativa, maybe try 33% less base nutrient and go from there.

 

[Aqua Man]

Yes full tsp per gallon of calmag till flush. You think that too much cal is locking out mag?

Yes full tsp per gallon of calmag till flush. You think that too much cal is locking out mag?

Yeah its possible... high P increases Mg demand and Ca and K reduce Mg available. So it could be in the ratios.

I cut cal mag after stretch by half then all together after swelling. I also reduce the Cal nit after stretch and again after swelling.

I mean it's worth a shot and can only really help a bit. After swelling there is not much need for cal at all. K is in high demand mid to late flower but P not so much. Imo high cal mag is responsible for more than a few K issues mid to later in flower.

 

[Frankster]

If I were to take a stab I would be looking at P&K as the causing factors here also.

It's pretty obvious that K's had an issue here at one time or another.

Likely a ratio thing as aqua suggest. I would consider restricting phos a little, and see if things improve. These things are always an educated guess, nothing more, IMO. But phos is certainly one of those that are commonly overdone IMO. Especially if you were pushing it early.

I generally have evolved into not even increasing it until almost the 2-3rd week into flower, and if it's not being up taken, it's simply accumulating in the substrate. Phos doesn't leach very well, that's one of the reasons I've started to restrict this mineral more. K generally will burn or whatnot, but it's seemingly easily flushed out, otherwise.

Phos is really a troublesome mineral on many fronts IMO, especially in soil or substrates, kills of your fungal biome, ect...
disclaimer: I'm not suggesting this is the problem 100%, but I've seen it cause problems such as these.

 

[ComfortablyNumb]

Phosphatases.
You may not be absorbing phos correctly. Consider adding some phosphatases (enzyme for phosphorus)

 

[Frankster]

Also inspect your pH ranges closely. Keep in mind that phos is generally absorbed at high pH levels than the rest....

mag, cal, phos all have tight ranges that I always consider, because I keep everything below the root line acidic.
You might could try a high pH foliar at that stage and still be alright.

Usually early on in flower, if I'm going to load some phos, (I use dipostassium phosphate above, and monopotassium phosphate below) I generally do it with a foliar at a high pH range. Say 100 ppm or so.

 

[Frankster]

So this is a hydo setup, is that correct? Or a soil grow, I'm not exactly clear on that part.

 

[Aqua Man]

I'm sure @TripsRabbit has his basis covered. I know he is pretty accomplished at troubleshooting so imo it's likely something not so common.

 

[ComfortablyNumb]

Phosphatases.
You may not be absorbing phos correctly. Consider adding some phosphatases (enzyme for phosphorus)

I suggested this because you mention a difference between indicas and sativas. This could be the issue because of genus uptake characteristics in the Sativa.

 

[Aqua Man]

I suggested this because you mention a difference between indicas and sativas. This could be the issue because of genus uptake characteristics in the Sativa.

Yeah all plants have slightly different needed.

 

[TripsRabbit]

So this is a hydo setup, is that correct? Or a soil grow, I'm not exactly clear on that part.

No, I grow in half coco chips and half coco husk. I do have an auto watering system but I only hook it up for mid flower and this one was hand watered.

 

[TripsRabbit]

My problem is that I'm always busy and I have a few plants that LOVE the fertilizer. I can give them about whatever I want and they always look amazing so I always mix my stuff pretty strong. Sometimes when I get a sativa pheno of a new plant I just can't get the ratios right.
I think that you guys have given me some great ideas and I really appreciate all of the insights.

 

[TripsRabbit]

Continues to look worse, it's only supposed to have a week left but it looks stunted.

Meanwhile right next to it on the same feeding schedule, look at this beast.

 

[Glassdub]

This popped up mostly on my Chemdog plant top growth, so its immobile my runoffs have been acid 5.2 so I've been assuming lockout of cal/mag, been 3ml a gal was planning on adding some potassium bicarbonate next water to bring up the pH, after reading this I'm not sure if I should drop the cal/mag the water is mineral free.