Should I be worried about the tips of the leaves?

I’ll copy a support ticket over here if you want, but I’m using GH Flora trio, cal mag, armor si, and hydro guard. ph=5.8 but it’s been trending down lately. Been able to keep it in an ok range (never lower than 5.6, or higher than 5.9)

About 17 days on 12/12.


Do you know your runoff PPM? That looks like nitrogen toxicity.

I’m RDWC, so no runoff. The nutes have a PPM of 1080 minus the 170 that the filtered tap water is, so effective nutes of 1010 today.

Looks like a bad case of nitrogen toxicity, heat stress, and/or nute burn.

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From those options, my guess is that I am pushing the nutes a little hard. I don’t think it’d be too much nitrogren, as I’m following a ‘medium’ schedule direct from GH. Heat stress is unlikely, air temp is ~75, nute temp ~73 (yea, that should be lower, but I am using Hydroguard, and the roots look fine).

The issue on the leaves corresponds in time to some battles I’ve been having with pH – my controller is set to keep it at 5.8 using pH Down (normally it creeps up), but lately it’s been creeping lower (to ~5.6-5.7) and when I top-up with filtered tap water, PPM=170 pH=7.5 or so, it pops back up to 5.8. I can’t imagine that a few hours of 5.6 would cause this…

Yeah from the looks of it, it definitely didn’t happen overnight. When’s the last you changed the reservoir?

When those pictures were taken, it had been 7 or 8 days. I’m scheduled to change again this weekend (14d).

I agree with everyone else it looks like a nitrogen toxicity and heat stress maybe a little bit of nut burn

Ok. Maybe I’ll do a Rez change today instead of the weekend. It doesn’t seem to be getting worse.

Hi. My name is Jungle, and I’m an idiot.

This is the THIRD time I’ve read the ml/liter and converted to ml/gallon wrong. The first two times, I underdosed CalMag. That’s not the end of the world, I suppose.

This time I overdosed (x3.8) ArmorSi. That explains why I’ve had trouble with my pH recently, and hopefully explains the plant behavior.

Changed nutes, carefully added the correct amounts of ArmorSi, CalMag, GH FL Micro/Gro/Bloom, and Hydroguard.

Hopefully it’ll be ok. Maybe what I saw was an oversupply of K?

Could’ve been potassium as well!


I had no spots, but more importantly I had overdosed Armor Si by about 3x, which is mostly K… which is why I conclude it was K, not N or P.

Sorry, actually I think we’re agreeing. K = Potassium.

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