Googled it, need you guys

got home from work everything's looking amazing and she's doing really well, 21 days old she's got new nodes flying out everywhere and pestils popping up to. Just don't know what these yellow leaf tips are. They are only at the top of her on the fresh leaves, I don't know whether it's my circulation fan causing wind burn or a nute deficiancy or is it that she's grown closer to the light and it's too much for her. It's a 250w hps and it's about a 12-18" off the top ? Also got these little yellow dots any ideas can't find a definite diagnosis on google so I need to pick you guys brains

Looks like nute burn to me. I see some purpling on the leaves. If that's not normal for your strain, that's something to consider. I only saw one spot. That could be from a water droplet magnifying the light, causing light burn.

What nutrients do you feed? What soil do you use? Measure the PPMs of your nutrients, and the runoff. I don't ph my stuff, but in your case (not knowing what's happening) it could be useful to know the ph of your runoff.

Feeding for 20-30% runoff is always a good idea (unless you're using expensive nutrients and don't want to waste money. In which case, you probably fell for some hype -- you're losing money anyway.).

This would fit better in the "problems" forum.

It's a royal queen creamatic they sometimes have purple, it's only on the leave stems like little purple dots but only on the bottom two leaves, I'm guessing it's nute burn. If I'm going to flush it won't it over water and upset it ? I'm new to this she's my first plant

Get a ppm meter and monitor your runoff ppm. That will avoid the guesswork about whether you need to "flush." The HM EZ-TDS is about $15 US on Amazon. You can make your own calibration solution with 1g table sat in 1L distilled water. (Gives 1000ppm). The meter's display is multipled by 10 when above 999. Watcing the runoff trend will give you an idea of what's happening when something happens. (For me, above 2000ppm is when I'm heading for trouble.).

Your plant seems young for salt buildup. The PPM meter would also tell you the strength of your final nutrient solution. That would help you know if you're erring too high or low. You also need to be concerned with the ppm of your tap water if you're using that instead of pure (RO) water.

For your first grow it looks very good. You want to be sure to let the soil completely dry between waterings. The soil ph rises almost a full point as it dries, making a wider range of nutrients available. If you water too frequently it holds the soil more acidic. Common first-grow mistake. You can let it dry until the leaves droop. Lift the container to get an idea what it feels like. The leaves will perk up 30 minutes after watering. I wouldn't do this a alot. I'm sure it is stress. But, it's a useful tradeoff to overwatering due to not knowing what "dry" feels like. I determine when to water just by lifting my containers.

If it were me, I would let it dry the way I said, then feed with 25% less nutrients, but 50% more quantity so you get *a lot* of runoff. See what happens. But, a TDS meter will give you information so you aren't shooting in the dark.

Do you have a ph meter? There is an inexpensive Etekcity meter on Amazon which comes with calibration solution (packets you put in distilled water). I don't ph anything anymore. I think it's pointless in soil if you have things relatively close. It's an unnecessary expense IMO because you have to buy storage and probe cleaning solutions, etc. Measuring the PPM of what I pour in, and the PPM of the runoff tells me all I need to know. (I spent $60 on a Control Wizard Accurate 8 soil probe. That's useful for measuring soil ph. But, what I see is that my soil ph drops corresponding to the runoff ppm rising. So, I just watch ppms now. Amending dolomite lime into the soil may be prerequisite to not phing the nutrient solution. I add 1 to 1.5 Tbsp to a gallon of soil, mixing it in. I use Fertilome Hy-Yield Agricultural Lime. You have to be careful what you get because there is hydrated lime which is too strong and toxic. Dolomite should have carbonates listed on the label, and the ratio of elemental Ca to Mg should be close to 2:1. Other carbonated limes with higher Ca ratios are calcitic lime. Hydrated lime will have no carbonates and almost zero Mg.).

In case anyone's following this, he's started a duplicate in the plant problem forum: https://www.rollitup.org/t/nute-burn-light-burn-wind-burn.891606/

That's really helpful I don't know the ppm of my run off unfortunately, I'm using seedling soil which had mutes in it anyways and I been using half strength veg feed (samurai) I been using the same mix of feed for about a week and it was the last of the mix before I went to bed last night, thee other watering I know not to over water I think I've got that down to a T however I did put my light schedule on 22 hours last night rather than 18 and that's when the problem occurred so I'm guessing it's something to do with that. Someone said heat stress but my tent doesn't get over 28 degrees that is maximum heat but over night it should of easily been at 25. My water is oh after the feed is in and it's reeding 6.2 and that's what I'm lookin for right ?

6.5 is preferable for soil. But, if you use dolomite lime in the soil it shouldn't matter much. (I don't ph my nutrients). What is the ph of the runoff? This is a bogus measurement because you have to do it just right for it to mean anything. Google for NCSU Pour-Thru Method to see what I mean. When I ph'ed my runoff I would water slowly, in stages to let it saturate. Let it sit for awhile, then water for about 1cup of runoff (hopefully the stuff that saturated.). That will tell you whether you have a serious problem or not.

But, you really need a TDS/PPM meter. If you're in europe it may be called an EC meter. You can convert EC to PPM by multipling the EC number by 1000, then divide by 2. (1 ec = 500ppm). It's a little more complicated than that because there are varous TDS standards. But, that's the general rule.

Without knowing the strength of your nutes nor how your runoff may be increasing in strength, you're shooting in the dark.

It's either the start of heat stress or nute burn. They both start with that yellowing of the tips. Do you have a fan blowing air between the light and plants? Are you venting your hps? I found my 250w was causing this when I was not venting properly in my wardrobe and I had the light 2ft above the plants.

If you are venting the light, it's probably nute burn.

Aussie Aussie Aussie

dopeleader said:

Aussie Aussie Aussie

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Oi Oi Oi

I'm going to try the run off method today when I get home, also I haven't got a cool tube but I got a good ventilation system going and I got a circulation fan blowing between the light and plant. When I place my hand on the top part of the plant I can feel the fan pretty strong and the temperature drops a lot, it's on the fresher leaves of the plant I don't know what it is, I'll test the ph of my run tonight and let you know how I get off.

I would pick your light up a bit, the leaves under the ones with the yellow tips you can see the edges starting to roll in, but its very minor. I would give it a couple days before changing anything else and creating other problems by flushing/feeding. They look healthy to me. I wish my first attempt came out like that. You mentioned if you flushed the soil wouldn't you be overwatering it? When you hear that term overwatering it isn't the amount of water you're putting into the soil its how often you do it. If you poured a five gallon bucket of water onto a sponge it would be soaked but most of the water would run off and the sponge would be dry in a couple days right? If you took the same sponge and the same five gallons of water but only dumped a gallon a day on it, its gonna to much longer to dry and when problems start in your root zone.
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KryptoBud

Thank you I'm glad you guys think I'm on the right track I did lift the light last night I took it up an extra two inches, hopefully the yellow hasn't got worse i check when I got home. Thing is I been feeding her the same for the last two weeks I didn't introduce nutes until ten days and she had some decent leaves. There are little purple dot on the stems of the leaves but only the bottom four leaves all the other nodes are bright green so if the purpling isn't strain and is stress I think it's very minor, as soon as I changed the light schedule that's when it occurred so I dropped it back to 18 and maybe it is the light because she's growing fast (getting closer to the light. Thank you for the over watering info you made it a lot clearer to me now

Agree with Krypto mate. I wouldn't go flushing unless you just upped the dosage or did something different/new with the nutes. Raise your light a bit. 12" might be be a tad too close if you're not venting it. I think the only way to know whether it's nute burn or heat stress is process of elimination. If you've been feeding the same amounts and they've been fine up until now, it's highly unlikely that it's nute burn. You did mention that the plants grew closer to the light. If I read properly

A 250w can still throw off some heat. I live in a warm climate and could only ever get my heat problems sorted once I started properly venting the light. I mistakenly thought by using a 250w I'd get away with not needing to ventilate properly. How wrong I was. I could get away with it, but had to have the light way too far away.

I see the curling Krypto mentioned now. That's either heat or wind stress AFAIK. I have read deficiencies can cause it but that info was suspect. You mentioned it's blowy up the top of the plant. One of my girls hates this and gets the same curl if there's a fan blowing straight onto her. Temperamental woman that she is

Fans are.m important but a fan needs to be blowing at or towards bottom of plant to keep all air circulation. The tops don't need much. I sometimes make the "wind" blow hard today and barely anything for the next day or so I change it up as nature always throws curve balls.

Heat stress,or wind burn.

I'm going nute burn but could be wind...I run a 400 watt HPS open bulb around 13" above plants with no burn but I do have fan that blows directly across the bulb and the heat out from under the reflector.

anzohaze said:

Fans are.m important but a fan needs to be blowing at or towards bottom of plant to keep all air circulation. The tops don't need much. I sometimes make the "wind" blow hard today and barely anything for the next day or so I change it up as nature always throws curve balls.

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Was thinking about wind tunnels so I decided to rip a few bongs through the tent to see if I could get an idea of how the air was moving in there (plants removed of course). Had to thumb screw and haystack a cracker of a cone but it actually works. Haha! Anyway, by doing this I found that by positioning my 160mm fan just under the coolcube, pointed towards the exhaust causes the heat from the lamp to be exhausted out faster. Fan just needs to be pointed at the direction of the exhaust intake too. I need to test this out further when my current grow is finished. Get the boys around and we'll rip a boatload of cones through the tent

I have not needed to upgrade my shitty booster fan to cool the 600w light upgrade. I don't filter either but my climate is hot and I have no trouble keeping the canopy right under the lamp at 1/2 degree to a degree max above room ambient.