Iron deficiency?

[Cali MedPatient]

Hi,

I've been having a problem in my veg room, I think it's an iron deficiency, but I can figure out what's causing it. I've been growing on this property for 7 years, with the same water, and it's a new problem that just showed up a few months ago.

I was battling a pythium problem, so I gutted my veg room. I threw out every root ball, completely emptied the room, bleached the floor, painted several coats of fresh paint on the walls, bleached everything, built new tables and added a UV sterilizer to my Evolution 1000 RO filter (I have well water). When I put some new plants in the room, I potted them up in Promix HP, which I hadn't used in years. After a few weeks, I started seeing yellow new growth. I started double and triple checking my pH with the drops that I was using, and bought a few pH pens to make sure that I wasn't just messing up the pH. They started looking green again. But it happened again, and this time the new growth was completely white. I ended up tossing most of those plants, but I kept a few and was able to get them to grow new green leaves, but the white leaves never became green again. I started some new clones, they were doing pretty well, but it keeps happening, sometimes worse than other times.

I've been using Promix HP. I was using Lucas formula nutrients for years, with Cal/Mag, but when this occurred, I tried MaxiGro, then Floranova bloom. I've had the problem with all three. I hand water. I just started using Sensi grow hoping the pH perfect will help, but it's too soon to tell. When I move plants into the flower room, I pot them up in Coco and haven't seen this problem in there at all, even though I use the same water.

I have RO filtered well water with a UV sterilizer. I've read that UV can knock iron out of nutrients, but the UV is before any nutrients are added, the RO fills up a tank that I pump out to fill my mixing tank. Can the UV have an effect on the iron after it's gone through the UV?

The plants are under air cooled 600watt MH lights, 4-5 feet above the canopy. The temps are 60-80 degrees, with CO2 at 800 ppms. RH is 50-60%.

Does this look like iron deficiency, or is it something else? Thank you for sharing any ideas you might have!

 

[Andyo]

UV

UV

UV light precipitates iron out of solution

 

[maimunji]

Looks like Off gassing

 

[troutman]

At a high soil pH. Iron isn't really available to plants.

Molasses is rich in iron. I use some once a week. A few good drops per gallon of water is all I use.

Worse case scenario, throw a few rusty nails in your watering container.

 

[Cali MedPatient]

AndyO Do you think running water through a UV sterilizer, and then adding nutrients to it later can cause the iron to precipitate out?

maimunji I agree, it does resemble outgassing, but wouldn't outgassing happen to all of the plants in the room?

troutman I suspect it's the pH. I have crazy pH swings. Water comes out at 7. Add nutrients, it's 4.5. I put some up in to get it to 6.3. Come back two days later, pH is 7-8. It takes a lot of down to get it back into range. I'm hoping the pH perfect will help.

 

[maimunji]

When I move plants into the flower room, I pot them up in Coco and haven't seen this problem in there at all, even though I use the same water.

This make me think its off gassing I can't see where you say there is other plants in same room but this is maybe because my english is poor. Anyway try to veg in coco medium maybe old promix is reason.

 

[Cali MedPatient]

Hey maimunji, I think you were right. I took a few plants out of the room, and moved them to my friend's room, and they looked better in 24 hours. I turned off the co2 in my room, and turned on a ventilation fan, and my plants are already greener!! Thank you!! And I think your english is pretty good!