Nutrient burn or deficiency?

Burnt tips and yellow lower leaves

Flipped switch 29 days ago
600w HPS high par
Durbin poison or Blueberry(mixed them up as seeds )
73-77 degrees in the day
45-55% humidity in the day
Medium- 100% perlite in 5 gal smart pots, about 10% runoff each watering.
Water- every 3 days with 3L/plant
Nutrients- perfect ph 5ml micro, 5ml grow, 5ml bloom, 5ml flora nova bloom = about 750ppm
Ph - 6.0
Overall I am happy with my grow, plants look good. My last few grows I have struggled with burnt tips. I just want to grow the best plants possible.

I haven’t figured out if my yellowing leaves are a potassium or nitrogen deficiency, or if I am overdoing the nutrients and just strait up burning them with too many nutes/nutrient lockout.

some leaves are burnt all the way along the outside serrated edges.

Anyone have any idea where I am going wrong?

You're giving 5ml floranova and 5ml of another bloom? Sounds off....that would equal near 1200-1400ppm (Hannah scale) for me. Way too hot. 5ml floranova alone would probably be enough.

5pm if each per plant per watering with 3 liters of water. It’s 1.6ml each per liter.

you think too hot? Maybe my ppm meter is broken.

What is Hannah scale?

Can too many nutes cause yellowing leaves?

Reynom14 said:

What is Hannah scale?

Can too many nutes cause yellowing leaves?

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Yep it sure can...always calibrate your ppm meter. I usually calibrate at least once a month. Hannah scale is how we equate PPM to EC for Hannah Meter...there's others you gotta check your meter. Also, I think 100% perlite needs watering everyday. Maybe I'm wrong on that.

Stick to EC, that's what the meter is actually measuring.

PPM is a derived scale and only applies to NaCl (or KCl for the 700 scale) and is not indicative of the elemental ppm of the nute solution

Using ppm to describe nute strength is both misleading and ambiguous

Alright I’ll try to calibrate and see what it says then.

surprisingly the 100% perlite holds water decent(smaller grain) and my plants have gotten huge so fast. I feel if I can’t get it right perlite is the way. Way way better than soil.

Reynom14 said:

Alright I’ll try to calibrate and see what it says then.

surprisingly the 100% perlite holds water decent(smaller grain) and my plants have gotten huge so fast. I feel if I can’t get it right perlite is the way. Way way better than soil.

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I'll do a hempy bucket with 100% perlite one day and do a test...I'd do it with hempy because it'd be easier to gauge how much water is in it. But yeah keep your EC low, like 1.2-1.3 and you shouldn't have any issues. You can use that floranova bloom alone fine, but I've found better results with just grow nutrients til the end.

Also perlite is sooooo light… so you can feel the water weight really easy

Reynom14 said:

And thank you.

what EC do you recommend at different in veg and flowering?

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I start at .8EC the day the seed pops til end of veg...once I flip I gradually increase to about 1.2-1.3. I've noticed if I go any higher, instant tip burn so I back off. You'll have to see what works for you with your water etc.

Right on. Thank you brother

Reynom14 said:

Right on. Thank you brother

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inth3shadowz said:

I start at .8EC the day the seed pops til end of veg...once I flip I gradually increase to about 1.2-1.3. I've noticed if I go any higher, instant tip burn so I back off. You'll have to see what works for you with your water etc.

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Why would my EC show up as 350? This is just plain tap btw. Ppm shows up 175.

Reynom14 said:

Why would my EC show up as 350? This is just plain tap btw. Ppm shows up 175.

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Imagine there's a decimal after the first number...so you're at around .3. That looks like an el cheapo meter though, hard to say how accurate those are. I'd suggest investing in a decent one.

PPM displayed by the meter is 1/2 of EC: the meter measures conductivity, not ppm.
The ppm is simply a derived value and not representative of elemental ppm (unless you're measuring table salt)

1000 microsiemens (mS) = 1 millisiemen (µS)

@inth3shadowz btw I watered after just two days (5gal 100% perlite) and my pots still took the same amount of water. 15% runoff or so off with 3 liters.

my plants haven’t dropped ever though, so it’s not like they were acting under watered. But if the pot holds the same water after 2 days as 3 I figure they must be thirsty.

And you were right on nute burn, a little color is coming back in those lower leaves.

3 days ago was 1tbs molasses to 9L and then yesterday was 1tbs novabloom to 9L.(split for 3 plants.

the yellowest leaves (that didn’t crisp) look this this now.

Still proud of my girls, 32 days since the flip. They are as big as I’ve grown, and I next time should be even better without the burn!

Reynom14 said:

And you were right on nute burn, a little color is coming back in those lower leaves.

3 days ago was 1tbs molasses to 9L and then yesterday was 1tbs novabloom to 9L.(split for 3 plants.

the yellowest leaves (that didn’t crisp) look this this now.

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Don't give molasses to your plant lol just floranova.

Reynom14 said:

And you were right on nute burn, a little color is coming back in those lower leaves.

3 days ago was 1tbs molasses to 9L and then yesterday was 1tbs novabloom to 9L.(split for 3 plants.

the yellowest leaves (that didn’t crisp) look this this now.

Click to expand...

You can skip the molasses. More bro science.