Calcium Deficit?

[banjoslaughter]

Good morning! I have a 5 week plant that is starting to have issues. Last week I noticed iridescent marks on my largest fan leaf. I thought it was damage from earlier in the grow as Inhad to switch this plant from autopot to DWC to rescue it from a dumb error. I removed the leaf and am now starting to see these iridescent spots turn to brown spots within 24 hours. My gut is telling me Calcium deficit; but I am not sure. Full disclosure, this is my first cannabis plant, but I’ve been growing lettuce for years, so I am a non noob noob. I am growing in dwc with a 3.5 gallon bucket and hydroton. I switch out the nutrients every week using GH Flora trio. I add calmagic as well as hydro-guard. My water temps are a little high at 73-74, used RO water as my base, my EC is around 1.7. I keep the PH around between 5.7 and 5.9. I use the Infinity 69 pro with the AC infinity humidifier, lights, recirculating fan, and in-line fan.

My gut is telling me to raise the PH to 6.0 to rule out Cal lockout.

I welcome any and all suggestions!

 

[Creeperpark]

Good morning! I have a 5 week plant that is starting to have issues. Last week I noticed iridescent marks on my largest fan leaf. I thought it was damage from earlier in the grow as Inhad to switch this plant from autopot to DWC to rescue it from a dumb error. I removed the leaf and am now starting to see these iridescent spots turn to brown spots within 24 hours. My gut is telling me Calcium deficit; but I am not sure. Full disclosure, this is my first cannabis plant, but I’ve been growing lettuce for years, so I am a non noob noob. I am growing in dwc with a 3.5 gallon bucket and hydroton. I switch out the nutrients every week using GH Flora trio. I add calmagic as well as hydro-guard. My water temps are a little high at 73-74, used RO water as my base, my EC is around 1.7. I keep the PH around between 5.7 and 5.9. I use the Infinity 69 pro with the AC infinity humidifier, lights, recirculating fan, and in-line fan.

My gut is telling me to raise the PH to 6.0 to rule out Cal lockout.

I welcome any and all suggestions!

Sorry you are having problems friend, wow what a big leaf. I would go by the table chart GH fora uses by the book. NOT LESS or MORE. Also, make sure the light is not too close. Your water temps are a little high.

64-72°F
The DWC water temp Celsius range is between 18-22°C - (64-72°F). It is important to keep the water temperature in this range because higher temperatures can lead to a lack of dissolved oxygen in the water, which can cause root rot and other issues. Google

 

[Stone]

That does look like calcium, but from your feeds I wouldn’t expect it.
Foliar feed the calcium for this issue as you dial out the original cause.

Those aren’t cause for big concern.
A whole plant picture would give us a better idea.

 

[diseasedmind]

Check for thrips

 

[linde]

Yes you are correct. Calcium won't be absorbed with that low of pH. Raise pH and deficiency will go away. Edit.... that was a month ago. I'm sure the op has resolved his problem by now.

 

[Onboard]

Yes you are correct. Calcium won't be absorbed with that low of pH. Raise pH and deficiency will go away. Edit.... that was a month ago. I'm sure the op has resolved his problem by now.

I appreciate that input though, and can confirm!

I was feeding lots of Ca at pH 5.5-6.0, and still had those exact discolourations. (Mostly on the lower leaves, turned into brown dead spots over time. I think.)
But after upping to pH 6.3-6.8, everything turned green again. It also improved P uptake (much less red stems and petioles), and Mg uptake, too.
I could also cut down on the overall feeding with at least one third.

 

[Creeperpark]

So what happened? Did your hydro setup fail?