yellowing tips, brown spots, Ca deficiency?

Hi, first time grower, 6 plants, bagseeds, day 23 of veg. 2 of the plants have nasty looking yellow tips on the lower leaves. Pictures say more than words.

I water, but have not as of yet fertilized. I just got my fox farms products today and will be using them tomorrow. Soil is too wet to water today.

2 175w MH, 6 or so 100w cfl's for lighting. Temp is always around 78-80. Low humidity <20%. Was thinking about putting a pot of water in there to evaporate off some moisture.

Three of the other plants look good, and one is a monster. They all have lots of side shoots and branching. Maybe they're just hungry?

I was looking around online and saw some pictures that seemed like they looked like my plants, and they were noting a calcium deficiency.

Any thoughts?

hmm doesn't look like calcium to me, looks a lot simpler than that. check out International Cannagraphic Magazine Forums - The Complete guide to Sick Plants,pH, and Pest troubles!

this is a very useful resource for almost ANY plant problem. Scroll thru til you see a pic like yours.

I used the other picture based plant diagnosis faq, the one from drugs-something.com that gets posted a lot around here, and it matches the diagnosis that I see in the post you mentioned too, that looks like a calcium deficiency.

Browning tips, with little brown spots appearing in the leaves later in development. I've had browning tips a bit for a while and assumed it was because I used a soil with some nutes in it, but now I'm thinking the level of nutrients was quite low, as the plants seem to have perked up after their first feeding with big bloom and grow big this morning.

I don't expect the quality of the lower leaves that look affected to change, but hopefully it won't continue up the plant...

We'll see.

there just hungry! there almost a month old and haven't eaten yet, give them a 5ml per gal dose of the grow big to start and they will perk right up. i always used the ff products as well. BTW liquid karma and thrive alive work great when used together with the fox farm fertilizers. also with the grow big and especially the tiger bloom you will have to use ph up to bring the water/ferts ph up to 6.0. the only problem i have found with the ff products is that they are WAY TOO ACIDIC to use without adding some ph up. just my $.02

I would also ask how often you are watering? Over watering often looks like other problems and a 3 week old plant shouldn't have a nute deficiency sufficient enough to cause that much yellowing unless you are growing in some sort of soiless medium that had zero nutritional value to start with.

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Originally Posted by doco

I would also ask how often you are watering? Over watering often looks like other problems and a 3 week old plant shouldn't have a nute deficiency sufficient enough to cause that much yellowing unless you are growing in some sort of soiless medium that had zero nutritional value to start with.

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i guess you are right, i always use a soiless mix and perlite mixed at a 1:1 ratio so there is absolutely nothing in there and my seedlings are usually severely deficient at 3 weeks if i have not fed them yet.

heck, I have no clue really, I just know what mine looked like when I was over watering is all, lol. Whenever anyone has a problem it's the first question I ask because once I quit watering so much, they took off like mad.

And I'm not shy with the nutes either so mine have never gotten to three weeks without them. I would defer to your experience and suggest he follow the feeding advice since I have seen the evidence of your great grows. :D

Well, I've been concerned about over watering, but I live in the driest place on earth practically, and when I water, I rarely get anything out of the container anymore, so I've bumped up the amount but not the frequency, which in my case is every 48-60 hrs.

I fed the plants. I followed the directions on the fox farms website and gave each 3 gal container 32 oz of food/water mix. That was at 11 am, and now at 10pm the top growth areas of the plants are going nuts and some of the side shoots have poked through the canopy. One plants top was kinda limp and it has strengthened and straightened.

I guess they were hungry. Good thing the FedEx guy came on Wednesday.

I don't hold out much hope for the previously affected leaves but they are all low on the affected plants.

Here is a macro pic of some of the new growth on one of the plants.

Thanks for the advice. Time will tell...

excellent, i'm glad it's working itself out. i water ONLY WHEN THE CONTAINERS ARE ALMOST COMPLETELY DRY i sometimes even wait till i see a slight droop before watering. this "dry" time is when the roots do the most growing because they are searching for the moisture at the bottom of the container, for this reason when i repot into 2gal or larger containers i always put a 1-2 inch layer of straight perlite at the bottom before adding any soilless mix, this way my girls don't always have wett feet. when i started doing this i noticed a much more steady growth pattern instead of just getting a growth spurt after each watering/feeding then only slow growth untill the next watering/feeding. i get more "hydro like " growth this way.it's just a trick iv'e picked up over the years.

Well, it's not over yet, I just tested the ph of the soil in one of the containers and it looked like it came in at 6.5...the affected plants are growing great new growth, but some of the existing growth is still browning. The tips on some of the new leaves are browning too, and now I'm starting to freak. Maybe it is still a serious nute deficiency, as I only fed 2tsp of big bloom per gal and 2T of grow big per gal at feeding time, which was 2 days ago. I used my moisture tester, but it gives different readings for different containers, ranging from 4-7 (10 being most moist) based on no real pattern...

I guess I'm going to let them dry out another day and see what happens to them. I'll check on them again before bed to make sure they're not drying out...

I'll keep the perlite layer in mind for the next grow, I should have done that this time, as I've done it before in other container grows...of other flowering plants...

Yes concentrate on your new growth....the affected leaves won't improve. Just ignore them an concentrate on your new, green leaves.

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Originally Posted by herbaltivo

I just tested the ph of the soil in one of the containers and it looked like it came in at 6.5...

I guess I'm going to let them dry out another day and see what happens to them. I'll check on them again before bed to make sure they're not drying out...

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How did you test the Ph of the soil without watering them? I test the run off after I've watered or fed them. That allows you to see the effect the nutes had on the Ph too.

I used a soil tester (gasp) to test the soil. I took a sample from the worst looking plant about 3" down from the surface.

I started foiliar (sp?) feeding the affected plants tiger bloom last night, as I'm still thinking Ca, and the first ingredient in that fert is Ca based.

I don't understand, as only half my crop is affected (thank goodness) and they all came from the same soil. Now that I remember it though, the consistency wasn't all that uniform and I was in a hurry when planting, so that may be the problem. Next grow will be with fox farms soil since there is a local retailer that will have the potting soil in a month or so.

I'm off to the X-Games now, so they'll get a good 12 hours more to just sit and enjoy the fertilizer. It's already been 16 hours longer than I've ever let them go between waterings, so maybe I'm messing that up too...

Look for me on the TV!

why did you use big bloom, those plants are still vegging, you should be using the grow big only! also the brown tips is usually nute burn. for a 1st feeding you should have done as i said, 1 tsp(5ml) of grow big per gal of water then ph'd to 6.0-6.5 with ph up. you gave 10ml of grow big and also big bloom thats too much! also i hope when you said 2T of grow big you didn't mean to tablespoons because 2 tablespoons would be about 6 times to much ferts for a 1st feeding even without the big bloom which isn't necessary in veg anyway. good luck and remember start slow with ferts then work up gradually!

I need to find some litmus paper to test my water's ph. Where does one come by such equipment in a reasonably sized town but not a city? I can get the ph up at the fish store in town, wonder if they have ph paper too?

any fish store or even walmart will have a chemical ph test kit for around 5 bucks.

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Originally Posted by justaseed

why did you use big bloom, those plants are still vegging, you should be using the grow big only! also the brown tips is usually nute burn. for a 1st feeding you should have done as i said, 1 tsp(5ml) of grow big per gal of water then ph'd to 6.0-6.5 with ph up. you gave 10ml of grow big and also big bloom thats too much! also i hope when you said 2T of grow big you didn't mean to tablespoons because 2 tablespoons would be about 6 times to much ferts for a 1st feeding even without the big bloom which isn't necessary in veg anyway. good luck and remember start slow with ferts then work up gradually!

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The Fox Farm feeding chart suggests feeding 2 Tablespoons of Big Bloom (even during veg) in addition to the 2-3 teaspoons of Grow Big. Any opinions?