Fan leaves turning yellow and tips of sugar leaves turning brown

Hi,
I have an unknown strain plant that is going into the third week of flower. Couple days ago I noticed that 3 or 4 of the fan leaves where turning a blotchy yellow and the tips of some sugar leaves were turning as well. I transplanted it from a small beef tub into a 5 gal bucket the last of October. The soil I used was Promix organic. The only nutes I have been using is the Pure Blend Pro Soil Bloom 1-4-5 with a mix of 7mls to a 2 liter water. I have been feeding it once a week for the last 3 weeks. When I watered today with the mix I gave it enough to get some run off to check the numbers. To check the ph I only have the strips that only go down to 6.2, my color looked a little lighter than that so I am guessing around 6 ph, the ppm's were 1067. The ppm's of the mix before going thru the soil was 396. I am using a series of led spectrum light bulbs with a total wattage of 760. The water that I have been using is what my dehumidifier makes. The temp with lights on in the daytime is approx 23-24C and when off it slowly drops down 5 or so degrees. My 12-12 is 7am to 7 pm. Thats all the info I have at the moment. Any help on this matter would be appreciated. I would hate to lose the plant at this stage. Thanks

I am not sure if you can do photographs, but it would help to know where those fan leaves were. Were they at the top? Closest to the light? If you're talking 760 actual watts that seems like a lot to me.

Ukulele Haze said:

I am not sure if you can do photographs, but it would help to know where those fan leaves were. Were they at the top? Closest to the light? If you're talking 760 actual watts that seems like a lot to me.

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Thanks for the reply. The fan leaves are actually around the middle of the plant. I should have stated equivalent wattage. The actual wattage is around 110 . I will try to get a few pics to post.

Fred4 said:

Thanks for the reply. The fan leaves are actually around the middle of the plant. I should have stated equivalent wattage. The actual wattage is around 110 . I will try to get a few pics to post.

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Have you thought about using some different water ? A dehumidifier could be putting metals and who knows what else into your water which over time may be affecting your plant and eventually going into your body. Sounds like you are beginning to have a calcium deficiency being as you are 3 weeks into flower and at this time plants really use up the calcium to go through there stretch . I would start with the water and then the calcium . Just my 2 pennies though .

Cal mag?

I'm having a similar issue on 2 of my plants under Vero cobs. Yellowing of the upper leaves. Starts at tips and edges and goes in. I'm ready to harvest now and the sugar leaves and upper fans all went brown. 2 others in same soil mix getting same water etc but under Cree cobs are fine. I'm using a fish based nute in addition to my amended organic soil, and per instructions I ph it to 6.2. I use organic ph up that is calcium based. I've never PhD anything before. My leaves look like potassium deficiency and/or light stress. I raised lights. Carefully watered. Grown for 10 years. I wonder if I locked out the K by adding to much calcium? I have crab meal in my soil and oyster shell flour. plus fairly large amount of ph up each feed.

ChrispyCritter said:

I'm having a similar issue on 2 of my plants under Vero cobs. Yellowing of the upper leaves. Starts at tips and edges and goes in. I'm ready to harvest now and the sugar leaves and upper fans all went brown. 2 others in same soil mix getting same water etc but under Cree cobs are fine. I'm using a fish based nute in addition to my amended organic soil, and per instructions I ph it to 6.2. I use organic ph up that is calcium based. I've never PhD anything before. My leaves look like potassium deficiency and/or light stress. I raised lights. Carefully watered. Grown for 10 years. I wonder if I locked out the K by adding to much calcium? I have crab meal in my soil and oyster shell flour. plus fairly large amount of ph up each feed.

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you have ruled out mites 100% correct? checked with a loupe both sides of the dead leaves?

Yes. Ruled out first. Good point

ChrispyCritter said:

Yes. Ruled out first. Good point

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i found out the hard way on my first grow fricken mites! sometimes they just die out at the end of their cycle if your triches are cloudy just chop her

ChrispyCritter said:

I'm having a similar issue on 2 of my plants under Vero cobs. Yellowing of the upper leaves. Starts at tips and edges and goes in. I'm ready to harvest now and the sugar leaves and upper fans all went brown. 2 others in same soil mix getting same water etc but under Cree cobs are fine. I'm using a fish based nute in addition to my amended organic soil, and per instructions I ph it to 6.2. I use organic ph up that is calcium based. I've never PhD anything before. My leaves look like potassium deficiency and/or light stress. I raised lights. Carefully watered. Grown for 10 years. I wonder if I locked out the K by adding to much calcium? I have crab meal in my soil and oyster shell flour. plus fairly large amount of ph up each feed.

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Definitely could be lockout from excess calcium. You have a lot of fish products and are using PH up with calcium, which you’ve never used before.
if you have nice organic soil, toss out the PH adjusters. You don’t need them.
And maybe you don’t need all that fish byproduct either but if it’s worked before then just dump the ph up.

Thanks for responding. I'm using a liquid fish fert combo from the same company that makes Tribus. Its my first time using it and it really bottoms out the ph. It takes it down to 5.2 in the water and they recommend upping it to 6.2 before root drench. I've never checked ph in organics before this. I don't know what the issue is since only 2 of 4 plants showed the deficiency. The ones that yellowed were under the Vero at 400 watts. The 2 that are fine are under crees at 300 roughly so maybe it is light stress and I didn't catch it soon enough. My upper leaves looked exactly like potassium deficiency. Which I've read is just like light stress.

And sorry for hijacking this thread. I should have started my own @Fred4

Could be. I’d still dump the ph adjusters.
Light stress almost always shows a physical aspect as well, such as new growth curling.
Since you’re ready to harvest you’d probably have seen light stress earlier.
You tried some new stuff that didn’t perform as hoped. I’d go back to your regular routine.
Never been a fan of straight up fish ferts. Or shells. Too inconsistent.
Some guys do great with it, others like me try it, and move on next grow.
At least you got your harvest.

Hi, Thanks for all the the info. My son discovered that the ph was out of whack so now we have rectified that problem and hopefully that was it.
Now I need to purchase both a PH pen and a TDS pen . I would like to get something decent and reasonably priced , any suggestions would be great.