First grow brown spots on leaves help please

[Mikenike]

hey all I have been doing a ton of reading and cannot come up with an answer just a few possibilities and I wanted to know if I was on the right track or get input from some more experienced folks.

This is my very first grow one double grape and one forum stomper from Mephisto genetics. They are about 4 weeks old from seed in two 5 gal rdwc buckets. 4x4x6 grow tent with two mars hydro eco 600. Currently day temps are 85-90 with humidity 50-67% with constant 1500ppm of c02 during lights on. The first 2 weeks after sprout were without c02 and day temps were 77-79 with 35-45% humidity. Using AN Ph perfect line currently at 25% recommended strength.

My problem is brown rust spots on my leaves. I wasn’t as concerned before but now it is spreading to some new growth. At first I thought it was due to low humidity (as low as 25% sometimes) and now I think it might be a mag def. I am pretty sure it’s not bugs or a type of fungus I’ve inspected with a magnifying glass as well. I was unaware you were not supposed to mist during lights on. I’ve noticed the spots before I started misting but after misting more it seems like it got worse or it was already getting worse and the most didn’t help none. I have a mister with calmag ready to foliar feed during lights out now. Also on my double grape I noticed slight holes/tears that I did not cause as well. They seemed to have stopped but curious what the cause could’ve been. Am I on the right track? Any input would greatly be appreciated! First two are forum stomper other two is double grape.

 

[5BY5LEC]

Rdwc? If your not running some kind of calmag you need to be.
150ppm calmag goes in your water before anything else.
That should fix you up

 

[5BY5LEC]

Oh and if your doing Rdwc right you should never foliar anything unless its like sm-90 before you go into flower.
The plant is getting max nutes

 

[Mikenike]

Yes I am using RO water with 50% recommended calmag strength which is 35ml for 9 gal of water. The calmag foliar spray seemed to help the double grape plant (wasn’t much of a problem to begin with) but my forum stomper is still is still having this problem on upper new growth. Ph is 5.8-6.1 and currently ppm is about 900 (50% what AN recommends for week 3/4) still very confused thanks for the reply

 

[5BY5LEC]

Were your seeds fem seeds? JW
Wow 900 PPM. That seems like a lot for RDWC. You could just be having a lockout from too many nutes.
What is your ppm doing as your water level drops?
I ran 600PPM in full flower and now I am down at 500 again at week 6.5 of flower.

 

[Mikenike]

Yes both fem seeds. That’s what I was reading about this morning although the other plant is still doing great with no nute burn at all or any more brown spots. I will try lowering my ppm today

 

[5BY5LEC]

Cool. Are you staying at 900ppm as your water drops? Or is it climbing?

 

[Mikenike]

Ppm is actually 880 and yes it is staying the same as water drops

 

[Mikenike]

False I just checked my notepad. Started at 820ppm and is now 880 with lower water level

 

[5BY5LEC]

Ok. Use calmag first to get your water to 150ppm. Then nutes to get you to 400.
Watch your PPM's. If they drop you can go higher. If they stay the same or rise you need to lower your ppm.
Keep doing this until you find where it is dropping very slightly like 10ppm over a day or two.
If you get spots on the new growth, up the calmag by 50ppm.
PH is important also, once you find that sweet spot your PH will stay but keep in mind the less nutes you are running the less buffer your water will have.

 

[Mikenike]

Awesome thanks will do. Will dropping my ppm this much affect my other healthy plant?

 

[5BY5LEC]

It may but you are going to have to find an equilibrium between the two. You have two different strains in the same water, it will always be a bit of a compromise for both.

 

[5BY5LEC]

I had an OG in with my two MM's just to fill an empty spot. The OG was just shitty all the time while the other two were super healthy. I ended up just getting rid of the OG because it was a hassle. The two were doing so well I did not want to mess with it.

 

[Mikenike]

Ah yeah okay. Well then ill lower my ppm a tad. I’m significantly more happy with the healthy plant right now and the forum stomper is still growing it’s just having those spots and killing leaves so I’ll try something thanks for the help

 

[5BY5LEC]

Yeah. A lot of your nute strength has to do with how much air you are pumping into the water also. If you really have it rolling with bubbles you can get away with far, far less nutes. Like 50% on top of the 50% you are already running them at. Good luck man. Keep em healthy!

 

[budman111]

I am using RO water with 50% recommended calmag strength

You just answered your own question, go full dosage.

 

[5BY5LEC]

You just answered your own question, go full dosage.

Based on your likes you obviously have more experience than I do but the rec dose is 5/ml gal.
I get 75ppm per ml so that's like 350ppm alone of calmag? In Rdwc.
Just wondering.