What are these rusty spots? pics and details inside.

[SeanM]

Its the only plant doing it out of 6, its my single THC bomb.
Just started having the spots recently, I suspect my soil PH might be low. I plan to start my flush soon.

Any opinions?


Pro mix soil
Fox farm trio
feeding every other watering 100% of recommended

 

[Farang]

I've had limited success with THC Bomb because of ambient temperatures. apparently, this hybrid can't stand temps over 75F. where I live, it seldom gets that low.

I had those spots, too. I thought it was a calcium deficiency and used a foliar ETDA Calcium spray. I didn't see any difference and in the end, it seemed to have little effect.

 

[SeanM]

Temp is not the issue, I stay between 70-74F normally.

All 6 of my current plants are getting the same treatment, its the only one with spots.

I'm going to try a good flush this week see what happens, the problem isn't too threatening yet.

 

[Farang]

if you find out what it is/was, I'd be interested. it's only happened once to one of my plants.

 

[WizHigh]

Its a serious calcium deficiency salt build up. A flush is in need

 

[Farang]

I thought that, too, but efforts to flush and foliar feed calcium showed no improvement for my one plant which had those symptoms. however, there is probably no harm in trying that again.

 

[WizHigh]

No dont flush again. The leaves that were damaged wont correct it self or show improvement in fact they might yellow off and die. Look at the new growth and other leaves around the plant. Make sure you dont see any new signs of calcium or salt build up. Always pay attention to the new growth but over look the whole plant to make sure nothing new pops up.

I believe it was calcium because there were purple stems as well. Calcium def/over load will also lock out Phosphorus. So take it easy on additives or feedings as well. If your using Calimagic or Camg stop using it for a while.

 

[SeanM]

Yeah, I flushed mine and gave it a feeding at about 30% strength.

It hasn't got any worse.

 

[WizHigh]

You can use GH floraklean as well when doing feeding a or in between feeding. It stops salt build up and leaching of nutes on the roots.