Starting to have brown spots! Please help!

[Champ]

First time grower here! Rdwc, mars hydro lights at 36in from canopy at 40% strength, ph 6.4, ppm 350, water temp 72f, air temp 77f, humidy 64%, fox farms hydro nutrients. just had there 1 month birthday from seed. Just finished the 1st offical week in veg but the ladies are starting to wilt down and have brown spots! Please @Aquaman what are your thoughts on this isssue. Thanks so much in advance!

 

[Champ]

@Aqua Man

 

[Aqua Man]

@Aqua Man

Ph is waaay to high...

What is the water source?

Nutrients and any additives?

In what order are you mixing? and describe your exact process.

Sterime or live system?

 

[Nate_in_AK]

Have you validated that pH reading? Wondering if your meter could be wonky, because you're describing a pretty healthy environment in general. 6.4 is too high for a sprout-ling, but not terminal? (Not arguing with you AquaMan)

What are the genetics? Auto-flower or photo-period?

 

[Champ]

Thank you for your fast response! Water source is RoDi 0ppm, a sterile system (would rather do live but unsure), using cultivation nation 3 part liquid nutrients, no additives. The process so far is just mixing the nutrients in a mixing pitcher and pouring into the control and then adding general hydroponics ph down into the control but I havnt really been able to get it down. My first instinct was the ph was out of balance, tried to slowly lower it again today but I dont want to shock them. The genetics are photo. Thanks again any and everything will be a huge help, I'm loving this community here and spent hours on it a found you @Aqua Man to be full of knowledge. I will do what you suggest and keep you informed throught the process! Thanks too nate!!

 

[Aqua Man]

Thank you for your fast response! Water source is RoDi 0ppm, a sterile system (would rather do live but unsure), using cultivation nation 3 part liquid nutrients, no additives. The process so far is just mixing the nutrients in a mixing pitcher and pouring into the control and then adding general hydroponics ph down into the control but I havnt really been able to get it down. My first instinct was the ph was out of balance, tried to slowly lower it again today but I dont want to shock them. The genetics are photo. Thanks again any and everything will be a huge help, I'm loving this community here and spent hours on it a found you @Aqua Man to be full of knowledge. I will do what you suggest and keep you informed throught the process! Thanks too nate!!

Ok see you issues... lack of alkalinity and that leads to very poor ph control.

The PH down is ok but I prefer straight phosphoric acid.... little more stable.

Read this then ask your question as I'm sure you will have... do you have PH up by chance?

Marijuana pH Levels for Growing Weed: A Basic Explanation

In this article, we discuss proper pH levels for your weed plants; alkalinity, soil pH, tap water, and the effects of nutrients on pH when growing marijuana

www.thcfarmer.com

 

[Champ]

Yes I see what your saying about not having the alkaline buffer with the RO water . I just got in the fox farms cal/mag solution but havnt used it yet. I do have ph up as well from General Hydroponics. What order of operations would you suggest in going about our next water change, which will be tomorrow?

 

[Aqua Man]

Yes I see what your saying about not having the alkaline buffer with the RO water . I just got in the fox farms cal/mag solution but havnt used it yet. I do have ph up as well from General Hydroponics. What order of operations would you suggest in going about our next water change, which will be tomorrow?

I haven't used the PH up so we need a little test... you have a spare gal of RO to waste or maybe not waste case you can use it tomorrow.

Add 1 ml at a time if you can then measure the ppm.. bring it up to 75ppm and record how much you need to add to the gal to reach that.

After that. Add 3 ml of grow per gal of actual water... then ph down to 5.6.

 

[Aqua Man]

Then we gonna double check the ph 1 hr later and adjust if needed. From there check ph and ppm every 24 hrs and record. This way we can measure the drift and adjust the alkalinity if needed.

On to the next... any slime on the roots?

How are you doing your sterile regiment?

 

[Champ]

The ro flow rate/psi is a little on the high side so the water is coming out at about 15/20 ppm... so with that in mind my target for the test gallon would be 90/95ppm? When you say add 3ml of grow, do you mean the liquid nutrients or the cal/mag solution? Just want to clarify. Also the system is a 12 5 gallon bucket system with only 8 ladies in the system right now, the water was just lowered today to about an inch below the net cup. So I think we are at approximately 48 gallons of actual water, my question is does having those 4 empty buckets effect the amount of nuts I should add or should I just continue to focus on the actual water amount when totaling the nutes.Thanks again!

 

[Champ]

I wouldn't say slime on the roots but I did think the water was a little slimy, so yeah potentially slime on the roots would be safe to say. Not really doing anything in regards to a sterile regiment. Understanding the pros and cons of sterile vs live is still out of my wheel house at the moment but would love any info or best practices in regards to which direction to take. I say sterile because I sanitized everything from the very beginning but other than that not much I would say. I will keep detailed records of the ph from now on. I have some data on the ph values written down but it's to sperartic to be of much use I think.

 

[Aqua Man]

The ro flow rate/psi is a little on the high side so the water is coming out at about 15/20 ppm... so with that in mind my target for the test gallon would be 90/95ppm? When you say add 3ml of grow, do you mean the liquid nutrients or the cal/mag solution? Just want to clarify. Also the system is a 12 5 gallon bucket system with only 8 ladies in the system right now, the water was just lowered today to about an inch below the net cup. So I think we are at approximately 48 gallons of actual water, my question is does having those 4 empty buckets effect the amount of nuts I should add or should I just continue to focus on the actual water amount when totaling the nutes.Thanks again!

That ppm is fine I would just bring it to 75ish and we will see how the drift goes. Always wanna start low.

Is this a RDWC system or individual totes?

 

[Champ]

Rdwc with two 440 return pumps

 

[Aqua Man]

I wouldn't say slime on the roots but I did think the water was a little slimy, so yeah potentially slime on the roots would be safe to say. Not really doing anything in regards to a sterile regiment. Understanding the pros and cons of sterile vs live is still out of my wheel house at the moment but would love any info or best practices in regards to which direction to take. I say sterile because I sanitized everything from the very beginning but other than that not much I would say. I will keep detailed records of the ph from now on. I have some data on the ph values written down but it's to sperartic to be of much use I think.

Ok your gonna have to fix that or it's only a matter of time before you get root rot.

So you either need to add something like hydrogaurd or hydrogen peroxide... hydrogen peroxide will be cheaper but you need to add it consistently ever 3 days and thats an absolute must.

I prefer a live system and hydrogaurd while expensive is really good at its job. I have used southern ag fungicide and that works great too but can muck up the system a bit.

I would suggest searching here and do some reading on which way you want to go... but one or the other is a must imo.

 

[Aqua Man]

Rdwc with two 440 return pumps

Ok so calculate the total volume of water... we need to being the entire system to a proper ppm and ph no matter if you have 1 plant or 20.

 

[Champ]

Understood, I would say its roughly 45gallons of actual water..

 

[Aqua Man]

Understood, I would say its roughly 45gallons of actual water..

Ok so 135ml of grow in the system... but need to calculate ml of the ph up to use.

 

[Aqua Man]

Should bring you around 350-400 ppm total. Then ph down... you will notice you need significantly more ph down. But that's what will create a more stable ph in the end.

 

[Champ]

I was looking at hydrogarud the other day... I think I will go that route. Which means a live system. I'm doing a water change tomorrow, it will be the first one so all of this info is great I really appreciate it. That ppm is roughly where its sitting now but I dont think I was using enough ph down out of fear of shocking them. How easy is it to shock them with to quickly ph fluctuation. So to clarify 135ml grow nutrients+ test result amount from gal pitcher x 45 gal for total ml of ph up + how much cal/mag? Then at the end after putting into the system then ph everything down to 5.6?

 

[Aqua Man]

I was looking at hydrogarud the other day... I think I will go that route. Which means a live system. I'm doing a water change tomorrow, it will be the first one so all of this info is great I really appreciate it. That ppm is roughly where its sitting now but I dont think I was using enough ph down out of fear of shocking them. How easy is it to shock them with to quickly ph fluctuation. So to clarify 135ml grow nutrients+ test result amount from gal pitcher x 45 gal for total ml of ph up + how much cal/mag? Then at the end after putting into the system then ph everything down to 5.6?

Ok so 45 gal here is the plan for the system.

Add ph up to hit 75 ppm... then add half dose of cal mag as recommended on the bottle... no more.

Then add 135ml of grow... thats for the whole system.

Then check ppm after letting mix for 10 min. Rough guess is about 400-500ppm total.

Then ph down to 5.6.