Grow Mediums Sick plant, brown spots, week 3

[ryanisgrowing]

Hey all! New grower here. I have 2 gorilla glue autoflowers on day 26. Noticed that one of my plants had started growing brown spots on one of the newer leaves and another set of leaves have started to yellow at the tips, maybe due to nutrient burn? This same plant had the same problem at the end of week 1 on its first set of leaves but I couldn’t diagnose it and it had stopped growing the spots anyway. Now I just checked them and I see they aren’t doing well at all under all that shade. They’ve been starting to yellow and curl downwards. I’m wondering if this could be a calcium deficiency but it looks more like a manganese def. Any help at all would be much appreciated! Will post pics.

Medium: coco/perlite 80/20
Light: mars hydro 600w, 21” from canopy
Water: RO
pH: 5.8
Nutes: canna coco line without cannazym
Last feed: 2 days ago @ 500 ppm, 5.8pH

 

[Yeatster]

Do you have CalMg? If not, I suggest you get some.

 

[ryanisgrowing]

Do you have CalMg? If not, I suggest you get some.

I have cal mag, been feeding about 2ml from the start until last feed, now I'm on 3ml. Should I add more? Also why does it say completed at the top of my post? can I remove that?

 

[Yeatster]

I have cal mag, been feeding about 2ml from the start until last feed, now I'm on 3ml. Should I add more? Also why does it say completed at the top of my post? can I remove that?

I didn't see the CalMg addition in your original post, my bad. How much water are you adding 2ml. to?

As for the "completed". I've no clue but, I'll try to find someone for you, to clear that up. @Dudeski @TheMongol [USER=36247]@Prophetiko can someone fine tune this thread topic please and ty[/USER]

 

[ryanisgrowing]

I didn't see the CalMg addition in your original post, my bad. How much water are you adding 2ml. to?

As for the "completed". I've no clue but, I'll try to find someone for you, to clear that up. @Dudeski @TheMongol [USER=36247]@Prophetiko can someone fine tune this thread topic please and ty[/USER]

Yeah I forgot to mention it. I've been feeding about 2ml/gal for the first 3 weeks and a few days ago I raised it to 3ml/gal. The spots literally happened overnight, my friend just told me its a pH issue since it happened so fast. I'm gonna flush it and hopefully that helps. thanks for the help

 

[Yeatster]

Yeah I forgot to mention it. I've been feeding about 2ml/gal for the first 3 weeks and a few days ago I raised it to 3ml/gal. The spots literally happened overnight, my friend just told me its a pH issue since it happened so fast. I'm gonna flush it and hopefully that helps. thanks for the help

Please don't flush until @Waira shows up. Flushing will only cause stress, when it could be an easy fix. Personally, I don't think it's a Ph issue.

 

[ryanisgrowing]

Okay I'll wait. I'm using a pretty cheap pH scale, only costed like 15 bucks. I had some leftover 9.18 pH buffer powder, put it in a 250ml beaker and my pH scale came out to 9.84. Which means I probably have been feeding like 6.4 pH thinking it was 5.8 I don't have anymore of the 4.01 and 6.86 buffer solution, is it ok to calibrate with only the 9.18? I ordered a new budget pH scale, don't have enough for the hanna ec/ph but this Dr. meter ph100 meter will work. I'm afraid to mix anything else with deceiving pH scale now

 

[Yeatster]

Okay I'll wait. I'm using a pretty cheap pH scale, only costed like 15 bucks. I had some leftover 9.18 pH buffer powder, put it in a 250ml beaker and my pH scale came out to 9.84. Which means I probably have been feeding like 6.4 pH thinking it was 5.8 I don't have anymore of the 4.01 and 6.86 buffer solution, is it ok to calibrate with only the 9.18? I ordered a new budget pH scale, don't have enough for the hanna ec/ph but this Dr. meter ph100 meter will work. I'm afraid to mix anything else with deceiving pH scale now

Hmmm, if your Ph meter is screwy Id be worried. Have you been storing it correctly? I will say, it will very likely be recommended to get a reliable, soil Ph meter. We can't all afford that, myself included. The thing is, if your Ph meter is off, even a decimal or 2, it makes a difference, exponentially. I stand by my recommendation and say, wait for the Dr. Waira. He will get you straight.

 

[ryanisgrowing]

I'll wait for Dr. Waira, I got a little time, the pots are feeling pretty light so I'd probably have to water at the latest tomorrow morning. I'm going to walmart to pickup some disposable pH strips since they're the most reliable, and I can use them until the new pH scale is here. I read that soil pH meters don't well in coco though, well at least the cheap amazon ones don't. I'm hoping this Dr. Meter pH meter will be sufficient. If not I totally don't mind using test strips for the rest of the grow at least I know the pH will be 100% accurate.

 

[Yeatster]

I'll wait for Dr. Waira, I got a little time, the pots are feeling pretty light so I'd probably have to water at the latest tomorrow morning. I'm going to walmart to pickup some disposable pH strips since they're the most reliable, and I can use them until the new pH scale is here. I read that soil pH meters don't well in coco though, well at least the cheap amazon ones don't. I'm hoping this Dr. Meter pH meter will be sufficient. If not I totally don't mind using test strips for the rest of the grow at least I know the pH will be 100% accurate.

I can't say, with certainty if the strips mentioned are any good. I am a believer of, you get what you pay for. Either way, I will reflect on a distant post from a respected grower (Can't remember who, and it's not verbatim) "plants move slow. Real slow. Try to slow down and move with the speed of them."

Good luck my friend, I will watch here.