Browning tips mainly on the top 1 month 1/2 into flowering

1) PICTURE OF PLANT check picks
2) Growing indoor or outdoors - indoors
3) Watering schedule - every 3 days soak the pot
4) Growing Medium - Soil
5) What stage of growth - 1 1/2 month into flowering.
6) Lights HPS 600watt half a 40-60cms away from tops of plants

So my girls are getting towards the end of the flowering stage, one plant is 1 1/2 months into flowering and the rest are about 1 month in. Now they started to show some browing on the tips of the leaves towards the tops a few weeks ago but it seems to have gotten a lot worse in the last 3 days.

I've just changed jobs I am away for 3 days at a time now.

At first I thought it was just the normal stage of the flowering seeing a few brown leaves but definitely not this bad. Then I thought maybe it was Cali-Mag deficiency so started topping up the water/nutrients with that but it only seemed to make the problem worse. Just to make sure it wasn't light burn I moved the lights further away and this didn't improve anything.

So would I be right in guessing this is not in fact deficiency but nutrient burn ?? And I should just flush them for a week.

Well just topped them up with some clean water 6.5hp and just about to leave for another 3 days, fingers crossed they improve and it's not actually a deficiency in which case they will be 10 times worse haha.

iknownothink said:

Well just topped them up with some clean water 6.5hp and just about to leave for another 3 days, fingers crossed they improve and it's not actually a deficiency in which case they will be 10 times worse haha.

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My personal opinion is that I would check three possibilities...
1. Light burn. You said you raised the light though.
2. Later stage mag deficiency. Did it start with tiny rust spots, lower to halfway up the plant? Mag deficiency will develop and start to look like something else if left untreated. I just treat with epsom salt. Make sure to let the soil dry pretty well before you water again.
3. I was going to say maybe nitrogen burn, but I don’t think so. Too much yellowing, and burn would be more noticeable on the tops. I’d say it looks more like a deficiency than abundance, but I’d definitely get other opinions... my best guess would be magnesium deficiency though

Phosphate and nitrogen deficiency and magnesium deficiency... What's your feeding regiment..

Just got back from 3 days away and they don't seem to be looking any worse so at least the flush didn't do more damage, I've just given them a good feed and upped the Magnesium and Cal levels to see if that makes them improve when I get back in another 3 days.

1. Yeah I'm almost 100% sure its not light burn as its not really focused on the tops of the plants as the buds are still nice and green.
2. I don't think it was rusty spots more like a whole leaf would start turning yellow then brown on the tips, first it was just one or 2 leaves and then in that last 3 days it went to almost half the plants leaves, but all the buds are still that nice dark green.

I'm just using the average A & B Bloom nutrients that the local hyrdo store sells. It's 5mls of each per 1ltr and also add 2.5mls of Cali Mag ( something very similar but in our local brand) per ltr. And I usually get 10ltrs across the 6 plants which lasts them 3 days.

So each plant would be getting say 1.8ltrs per 3 days approx 20mls of A & B Bloom and 5mls of Cali Mag.

I'll find out in 3 more days if the nutrient boost as made the problem better or worse.
One of them is going to be ready for harvest in about a week so its not the end of the world but the others have a month or so to go.

It's weird what ever soil I'm using seems to be great in veg, almost needs no nutrients at all added, however as soon as it gets into about a month of flowering I get this browning effect, The same thing happened to my very first 2 successful grows but those 2 plants were only tiny babies.