Fan leaves drying out at the bottom (going pale green, not yellow, not falling off)

[PurpleBuckwheat]

Hi everyone! I've got a 43 day old Red Sugar from BSF seeds that is in full flowering. It's been a really good and worry-free grow so far and she is growing really strong. This is my third grow and I think she'll be the biggest plant I had.

However, around 10 days ago the first set of leaves (one tipped) started drying out, then a couple of days ago the second lower set of fan leaves started being affected too, and now the third one is a bit dry at the edges (not a lot). Earlier I had a small issue with gnats and therefore I was slightly underwatering her and now the gnats are almost gone. Also, I was giving the nutes only half or 3/4 strength.

The most interesting thing that by now the growth is not affected in any way and she's growing really quickly and surprisingly well. And the leaves are not easily plucked and neither they go yellow. They simply dry out starting at the tips and edges, turning pale green/brown and do not fall.

The upper and mid leaves are looking great and there are no other issues whatsoever with the plant. Just to be on the safe side, I gave it full strength of nutes last watering (nitrogen and some bloom sugar nutes as well as some kelp) and I'll start watering her more often now as she started drinking a lot of water.

I do PH my water and PH has always been at 6.2 to 6.5 range. The medium is soil, pot size is 12 liters (3 gal), 55% humidity and 20 to 23 degree celcius temperatures. Earlier I was watering her with around 2 to 2.5 liters once a week (to get rid of gnats) until runoff, but I just started to give her 2.5 liters of water until runoff once a week and then 1 or 1.5 liter of water another time the same week. She's kind of thirsty with the pot drying out in 3 days.

I was thinking it's due to underwatering and moderate feeding of nitrogen, but I'm asking for help here in order to stay on the safe side and make sure it's not anything more serious. It's her watering time tomorrow. Should I add more nitrogen nutes (it'll be over the highest recommended weekly dose as per the nutrient manufacturer) or simply give it plain water? Anything else? Thanks for help everyone!

 

[Aqua Man]

Looks like nutrients may be a bit to high. But you have a mag deficiency and also looking like possibly could use more sulfur. So epsom salt at 1-2gram per gal will likely help ya. I would not be feeding those plants at full strength. Half should probably be good.

As for the bottom leaves I would just pluck em. With that dense of canopy your going to want to make sure you get good airflow anyways.

 

[PurpleBuckwheat]

Looks like nutrients may be a bit to high. But you have a mag deficiency and also looking like possibly could use more sulfur. So epsom salt at 1-2gram per gal will likely help ya. I would not be feeding those plants at full strength. Half should probably be good.

As for the bottom leaves I would just pluck em. With that dense of canopy your going to want to make sure you get good airflow anyways.

Thanks a lot for such a quick answer, mate! So the bottom leaves drying is not a problem, right?

I'll give her (it's one plant) plain PHed water tomorrow then and will be feeding them half strength everything after that. Talking about magnesium, the soil actually had some dolomite lime mixed into it as it said in the components. But I have Advanced Nutrient's Flawless Finish (and it has exactly magnesium and sulfur and nothing else). Can I add it instead of epsom salts?

 

[Aqua Man]

Thanks a lot for such a quick answer, mate! So the bottom leaves drying is not a problem, right?

I'll give her (it's one plant) plain PHed water tomorrow then and will be feeding them half strength everything after that. Talking about magnesium, the soil actually had some dolomite lime mixed into it as it said in the components. But I have Advanced Nutrient's Flawless Finish (and it has exactly magnesium and sulfur and nothing else). Can I add it instead of epsom salts?

Never used it and can't say the dose to use. But if that's all it is I would think that's fine. Epsom salt is cheap at any grocery store or pharmacy. Just make sure it's pure epsom salt and not fragrances added.

 

[PurpleBuckwheat]

Never used it and can't say the dose to use. But if that's all it is I would think that's fine. Epsom salt is cheap at any grocery store or pharmacy. Just make sure it's pure epsom salt and not fragrances added.

Thanks once more. Will update the thread with the progress in a couple of days.

 

[PurpleBuckwheat]

Updating here as tomorrow is her watering and feeding day. I gave it magnesium+sulfur as advised. The plant grows vigorously and flowering continues, the topic's issue did not affect growth in any way as it stretched for about 10 to 12 cm in just three days. She's 46 days old from sprout.

However, the leaves drying problem is still present and slowly progressing upwards. The second set of leaves is completely dry/necrotic by now, the third set of leaves is affected, and it already started affecting the fourth set of fan leaves too. I know that the plant is really bushy, but I don't like the idea of it affecting more and more leaves.

To me it looks like the plant is feeding on its leaves and consuming itself (please correct me if I'm wrong). But why? Underwatering? Something else? Is it serious? Don't want to lose the girl as she is growing so well. Thanks a lot to everyone!

 

[PurpleBuckwheat]

Just updating over here. Everything's well and the plant is growing perfectly. I decided to place a LED strip at the lower part of my tent on Friday and I think that did it. Drying of leaves almost stopped or at least slowed down to a pace that I can't really notice. Thanks everyone!