FFOF pH problem?

8 weeks into veg, have 4 plants under a black dog LED in 7 gallon smart pots with FFOF. The 2 biggest plants are a little beat up after a slight underwatering. Been only watering with tap water, no nutes. Tap water comes out at 6.8pH and 20-30ppm. Lights are on 20/4, temps 68-78F and humidity 40-50%. Will be switching over to RO water soon. Does anyone have any idea as to what is causing this? Looks like N toxicity to me.

BBbubblegum said:

8 weeks into veg, have 4 plants under a black dog LED in 7 gallon smart pots with FFOF. The 2 biggest plants are a little beat up after a slight underwatering. Been only watering with tap water, no nutes. Tap water comes out at 6.8pH and 20-30ppm. Lights are on 20/4, temps 68-78F and humidity 40-50%. Will be switching over to RO water soon. Does anyone have any idea as to what is causing this? Looks like N toxicity to me.

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Everything looks great under a purple light. If you want some help your gonna have to take pics with natural light or flash on your phone. ill check back with you later. GL

BBbubblegum said:

8 weeks into veg, have 4 plants under a black dog LED in 7 gallon smart pots with FFOF. The 2 biggest plants are a little beat up after a slight underwatering. Been only watering with tap water, no nutes. Tap water comes out at 6.8pH and 20-30ppm. Lights are on 20/4, temps 68-78F and humidity 40-50%. Will be switching over to RO water soon. Does anyone have any idea as to what is causing this? Looks like N toxicity to me.

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Looks fine to me from what I can see, which is nothing lol

stay smokin'

CanniHelpYou said:

Everything looks great under a purple light. If you want some help your gonna have to take pics with natural light or flash on your phone. ill check back with you later. GL

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Fair enough; my fault.
Pictures 1,3, and 5 are group shots of the four plants. Picture 2 is the second most affected plant(Back right corner). Picture 4 is the biggest and most affected plant (front left corner)

Shroominnm said:

Looks fine to me from what I can see, which is nothing lol

stay smokin'

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New pictures are up.

A lot of people amend FFOF with a cup of dolomite and extra perlite. I've had good luck using it straight out of the bag.
If you've been using that soil for 8 weeks, it's probably spent. You can add more nutes by top dressing the soil, or going with a liquid mix.
If I was going to mix extra stuff into a bag of FFOF, it would be worm castings, kitty litter (calcined clay), and a little extra phosphorus -- either soft rock phosphate or low nitrogen bat guano.

Chunky Stool said:

A lot of people amend FFOF with a cup of dolomite and extra perlite. I've had good luck using it straight out of the bag.
If you've been using that soil for 8 weeks, it's probably spent. You can add more nutes by top dressing the soil, or going with a liquid mix.
If I was going to mix extra stuff into a bag of FFOF, it would be worm castings, kitty litter (calcined clay), and a little extra phosphorus -- either soft rock phosphate or low nitrogen bat guano.

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Thank you for the reply. I normally have good luck with FFOF out the bag even without adding anything and normally by the 4-6 week point i start seeing deficiencies and then i start feeding, but the leaves are so dark green and curled that it appears their is still plenty of nutes in the soil. One thing worth noting is that last week the plants went underwatered for an extra day than usual and the two biggest plants started going way downhill compared to the two smaller plants in the back left and front right corners. I'm assuming this has something to do with it

BBbubblegum said:

Thank you for the reply. I normally have good luck with FFOF out the bag even without adding anything and normally by the 4-6 week point i start seeing deficiencies and then i start feeding, but the leaves are so dark green and curled that it appears their is still plenty of nutes in the soil. One thing worth noting is that last week the plants went underwatered for an extra day than usual and the two biggest plants started going way downhill compared to the two smaller plants in the back left and front right corners. I'm assuming this has something to do with it

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Were the plants wilting?
When in veg, I intentionally let my plants dry out to the point that they are just barely starting to wilt. Some people would say that this is unnecessary and causes stress. Meh, maybe they are right, but I can tell you that the root systems on those plants will be VERY robust and healthy when you are ready to flower.
When flowering, I never let them dry out completely. They are usually drinking so much that I've got to water every other day just to keep up.

Plant in pic 4 is being beat to shit by thrips. Those white dots and spots on the leafs are indicitive of this. Better look into it to be sure. My opinion only.

Jimmy Sparkle said:

Plant in pic 4 is being beat to shit by thrips. Those white dots and spots on the leafs are indicitive of this. Better look into it to be sure. My opinion only.

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Online photos do look much like that plant but I have been using neem oil once a week so i didn't suspect any insect issues

Chunky Stool said:

Were the plants wilting?
When in veg, I intentionally let my plants dry out to the point that they are just barely starting to wilt. Some people would say that this is unnecessary and causes stress. Meh, maybe they are right, but I can tell you that the root systems on those plants will be VERY robust and healthy when you are ready to flower.
When flowering, I never let them dry out completely. They are usually drinking so much that I've got to water every other day just to keep up.

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They didn't wilt much in veg until about last week when they went about 4 days in between watering rather than the usual 2-3. All of them were perfectly green with no discoloration, only some clawing. While being underwatered/recovering they began to get all the discoloration. I cleaned them up a few days ago when i returned home to remove any wrecked leaves on the lower branches. All 4 plants were topped a few weeks ago.

No doubt that underwatering has its place when it comes to some minor leaf cupping ,browning,yellowing ect its how it goes that is true. However, those white rasp marks are indicitive of those filthy beasts. They have a life cycle that unless caught and broken will continue to reinfest even with neem oil wich unless used peoperly is useless. I would check if I were you. I hope Im wrong.

Looks like I have a number of problems on my hands, may have to pick up some insect soap

Plants that start to wilt from lack of water always bounce back quickly once they get H2O. Something else is going on. Maybe you have spider mites that were waiting for the plant to weaken before making their move. It's actually more common than you'd think. I do a lot of outdoor growing so a few mites/aphids/gnats don't freak me out. Healthy plants can defend themselves. Sustained high brix practically makes them immune. Unfortunately, late in flower, they are gradually getting weaker as end of life cycle approaches. Plants also hoard sugar late in flower, which depletes microbes in the soil. This also weakens immunity, which is why a lot of growers use molasses or another type of sugar to feed the good dirt critters.

If you've got bugz, being in veg is a HUGE advantage. Trying to fix problems during flower is always much worse. Sometimes it's not even worth the effort...

Chunky Stool said:

If you've got bugz, being in veg is a HUGE advantage. Trying to fix problems during flower is always much worse. Sometimes it's not even worth the effort...

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Gonna switch to RO water for the next week or two and I'll post an update

If any fert has been added to the soil, this might the problem. you say you are at 8 weeks if I understand this right, but you like to add fert at 4-6 weeks. so did you add more fert that you haven't mentioned yet? if not, I'd do nothing to the soil and just let it be. you might consider going to 12/12 mode soon though if they're close to the screen.

polishpollack said:

If any fert has been added to the soil, this might the problem. you say you are at 8 weeks if I understand this right, but you like to add fert at 4-6 weeks. so did you add more fert that you haven't mentioned yet? if not, I'd do nothing to the soil and just let it be. you might consider going to 12/12 mode soon though if they're close to the screen.

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Haven't added anything to the soil. I usually start feeding in 4-6 weeks once i start seeing minor N deficiency on the older bottom leaves that I normally remove anyways. The leaves will slowly drain to yellow but do not show any other health signs (burning, curling, spots) besides the yellowing. For some reason on this run, the plants have been dark green and clawing from around week 3-4 until now. I planned on flowering by this point but am afraid to flip with their current state, especially the bigger two. The game plan is to switch to RO water for a week or two and get new growth to come in and fill the screen, and then flip

So here are the plants currently. Still not using RO water but did a test on my tap water and runoff. Some tops are reaching the net, but the new growth doesn't look super healthy. Tap water is coming in at around 6.8 and runoff at about 6.2. Caclium/Mg not found in the tapwater, but there is plenty in the runoff from the ocean forest. Little nitrate is found in the tap, but there is a decent amount in the runoff which tells me there is nutes in the soil still. So my current diagnosis is still a N toxicity, I'm just not sure why I am seeing it still at 8 weeks in.

Honestly, it looks like you are overwatering. This will bring fungus gnats and/or root aphids (harder to detect).
Before you actually see root aphids on the surface, your plants will look like they are magnesium deficient.

Here's a leaf from a plant that looks perfectly fine otherwise:


This plant was completely infested with root aphids:

It actually looked much worse a week ago. I didn't think it would survive, but letting it dry out completely has brought it back to life.