Older Leaves Looking Rusty ?

[mcaveman]

My buddy uses fox farms and grow in soil , seems like 4-5 weeks in flower the older leaves start to look rusty , is this some kind of deficiency? He uses filtered water 100% of the time and He does not add cal mag.
Trying to figure out how to attach pictures

 

[mcaveman]

Got it

 

[JWM2]

Hate to post a link from another site but this may help. I just had a bout of this recently. FFOF can be a pretty hot soil to run. I’ve moved away from it completely and my plants are way happier. Sad as at one time FFOF was a great soil that was easily manageable.

I like being able to bottle feed nutes to my plants so I can control the feeding of each plant on its own. I run several strains so this is just easiest for me.

I’m not saying for sure this is it but it might give you a few ideas or an ah-ha moment that will help turn things around.

https://magazine.grasscity.com/marijuana-nutrient-burn-1786/

 

[DismalDude]

Check the PH of the runoff,it looks like a possible lockout problem.

 

[JWM2]

Check the PH of the runoff,it looks like a possible lockout problem.

That’s another issue I ran into as well. Ph was really low causing lockouts. Once I got the ph into range it started burning them up. I was chasing my tail. It eventually got worked out but the damage was done and I learned my lesson the hard way. No more FFOF for this guy ;-)

I did run some FFOF with about 70% coco and that helped quite a bit. I just don’t want to mess with it anymore. After sifting through some soil I found huge chunks of bark and even small rocks and various other debris in it. Wasn’t always like that.

 

[Jimster]

I use Promix and just regular commercial ferts/nutes and don't have problems, but these look burnt, either by too hot of a soil or too close to the lights. I use wood ashes to sweeten the soil if too acidic but I'd check the Ph if the lights aren't too close to cause burning.

 

[mcaveman]

Definitely not to close to lights , I verify that with a heat temp meter. To say it’s the soil is possible bit why would it start 4-6 weeks into flowering ? Other than the leaves looking like that the buds look fat and happy. I will try to figure out the PH of runoff and report back .
Thanks

 

[mcaveman]

Also newer growth looks just fine . This is frustrating.

 

[JWM2]

If the new growth looks fine then it’s fine. The old growth will never recover. But as long as it’s on the right track now you’re ok.

Also do a slurry test. Take some soil and mix it with distilled water that’s at 7.0 ph. Use a 2:1 ratio of water to soil. Mix it up really good. Let it sit for 15 mins. Then mix it up again and let it sit for another 15 mins. Then use your ph meter and check the ph of the slurry. That should give you the ph of your soil.

Just make sure to get soil that close to the roots and not just on top.

 

[mcaveman]

Ok I will do the slurry test tomorrow. I already feed today so I cant get a ph of runoff yet BUT my reverse osmosis water phs around 7.4 and when i add nutes it was about 6.3. Are those number acceptable ?

 

[mcaveman]

Now following the link from the earlier post it does look like nute burn . Now I’m wondering if I should flush them

 

[hawkman]

I would just flush till for 2 if not 3 weeks if you can - want to do " extra flush "because of the nutrient issues. Nice plant !!!!! consider removing (defoliation) all the fan leaves if you have 2 more week because the leaves re-tail water also , this help drying --- Het break a fan leaf stalk and tatse it - if it taste bitter more flusj - if it taste clean most nutrients/chemical have been flushed (ref:Maxium Yield)

 

[JWM2]

You can flush them but if the new growth is looking good then you are fine. Flushing won’t revive the old growth and you risk flushing out the beneficial bacteria which will then starve your plants for nutrients and making things worse.

Imo the slurry test is the best method for finding the ph of your growing medium. And you don’t need to flush to do it. Just grab some soil and mix it up.

 

[hawkman]

You can flush them but if the new growth is looking good then you are fine. Flushing won’t revive the old growth and you risk flushing out the beneficial bacteria which will then starve your plants for nutrients and making things worse.

Imo the slurry test is the best method for finding the ph of your growing medium. And you don’t need to flush to do it. Just grab some soil and mix it up.

adding soil really helps even if you have to take some out of your pots Do this myself some time's and also use a "top sol dressing" when in flower

 

[mcaveman]

OK so i decided to do a flush and here is my numbers , My PH meter is broke.
R.O. water going
IN-EC260 PPM130
----------------------------------------------------------------
Run Off after
1 Gallon
EC3300 PPM1700

After 4 gallons
EC1100 PPM550

What does this tell us if anything?
Thanks

 

[hawkman]

forget waht the normal PPM is 1,000-1,500 ?? your flushing is working - how many days till harvest ?

 

[Rootbound]

Get ya a new PH meter. Runoff ppm was a bit high, and low ph usually comes with salt buildup with high ppms.

 

[CaliRooted]

Your PH got way out of whack