Hydroponics - troubleshooting leaf spots please help

[AdaminCO]

Good luck!

 

[Terminatorkader]

Rinsed roots. Very white Changed water. Added cal mag. Fingers crossed. Ph is at 5.88 in both right now.I only added fox farms big bloom, grow big and micro brew according to directions. Nothing else this round except a little cal mag. Will advance to week 4 additives next weekend when I know they have no issues

 

[AdaminCO]

Rinsed roots. Very white Changed water. Added cal mag. Fingers crossed. Ph is at 5.88 in both right now.I only added fox farms big bloom, grow big and micro brew according to directions. Nothing else this round except a little cal mag. Will advance to week 4 additives next weekend when I know they have no issues

Looking fresh!

 

[KingJohnC]

Can you please list all the individual products you are currently using and in what quantity per gallon, the water sources starting pH and the order you are adding the nutrients to the water source to determine if there is also an unwanted interaction causing the nutrient lockout?

Is there a reason for running the reservoir volume low? The total volume of the nutrient mixture largely provides pH stability for the cannabis plants requirements to access and use the elements in the nutrient solution.

If you are able to, spray off the brown slime coat from the roots as it is may cause root rot.

Please answer as best able

I have identified improper pH range for the nutrient solution, this causes the individual elements to recombine into more complex forms of nutrients unavailable to the cannabis plant for use. The damage to the plants leaves are from nutrient deficiency. The quality of the source water, order that the nutrients are added and in strength are critical.

It is a mobile nutrient deficiency the plant is attempting to use stored nutrients from older vegetative growth to supply energy for new vegetative growth. The leaves tips of the new growth are damaged indicating the cause is related to either nutrient deficiency or excessive nutrient strength levels. The damaged leaf tips in the new photographs indicate low nitrogen usually caused by pH imbalance and lack of calcium and magnesium. When pH levels are too high calcium precipitates into solid forms and is unavailable or locked out from the pH range the plants are able to access. The pale green colour indicates low nitrogen is available for the plants requirements. When the pH range is too high calcium and magnesium are unavailable which is required to process nitrogen for new vegetative growth. The cannabis plant are not able to access the solid forms of nutrients either suspended in the nutrient solution or precipitated solids.

The leaf damage on older fan leaves is caused by nutrient lockout due to improper high pH levels. The damage on older fan leaves are caused by potassium, calcium and nitrogen deficiency.

I am verifying the order of operation in use is correct and not at cause for the nutrient lockout.

Please re calibrate the pH meter.

What is the source waters pH and PPM strength if known?

In what order are you adding the nutrients to the source water?

How much of each component per gallon and what are you using?

What is the final nutrients solution adjusted pH to?

You want pH 5.8 for hydroponics. Each decimal point increase equates to a 10x difference in pH levels.

The nutrient availability chart posted is inaccurate for hydroponics.

 

[Terminatorkader]

So the ph chart I was referring to was incorrect. Does anyone have one that’s recent or correct? Should I start it at 5.8 and let it drift up through the day?

 

[KingJohnC]

The nutrient availability charts i have posted are close to the cannabis plants required pH range to access the nutrients in solution. The ideal pH for cannabis plants to access nutrients in hydroponics is pH 5.8, ideally the plants are either supplied with a sufficient sized reservoir to allow pH stability and maintain optimum access to the nutrients in solution.

Cannabis plants not only remove elements from the nutrient solution but also leach back harmful metabolites and different complex nutrient forms that are unusable to the plant back into the nutrient solution. The cannabis plants also can use more water than nutrients from the nutrient solution which usually also raises the nutrient solutions pH. to gain control of the nutrient solutions pH, more frequent pH adjustment is required until the majority of the cannabis plants requirements for the available nutrients are either used from the solution or the nutrient PPM strength rises and pH rises indicating the plant is now using more water than nutrients in solution or the complex forms of nutrient bond that are unusable plant waste has increased the nutrients PPM strength and requires the nutrient solution be changed.

You want pH 5.8 for hydroponic and soilless (peat moss and coco coir) and pH 6.5 for soil.

Here is a nutrient availability chart

Here is a different soil nutrient availability chart

 

[Terminatorkader]

Distilled water is at 6.81. Ppm is 124

There is 2.5 gallons in each bucket. I add to bucket 3 teaspoons per gallon of big bloom. Then 3 teaspoons per gallon of grow big. Then add .5 teaspoons per gallon kangaroots then .5 teaspoons per gallon micro brew. I mix then test ph and Ppm. It’s at this time I adjust ph.

I tend to go in the order in which fox farms lists them. I added nothing else this round except those items but did put in 1 teaspoon of cal-mag 1-0-0 to each bucket as well.

Currently the solution in the buckets are at 1385 and 1380 ppm. I had ph at 5.88 after the change this afternoon.

I was using that other chart and thought 6 to 6.4 ph was ok. After googling, there’s so many different charts for hydroponics it was hard to tell what info was correct. To say on their end a range of 5.5 to 6.8 isn’t exactly right.

I had just calibrated my Ph monitor with the three solutions in filtered water last week but will check it again.

Right now they are perky and reaching to the light. I always check after a change to see what their leaves are doing. There are two leaf stems with a little purple. The rest are green. The main stem is all green.

I place my plant on an empty 5 gallon bucket while I mix the one it will be placed into and do not put it in until solution is mixed well and ph adjusted.

 

[KingJohnC]

Distilled water is at 6.81. Ppm is 124

There is 2.5 gallons in each bucket. I add to bucket 3 teaspoons per gallon of big bloom. Then 3 teaspoons per gallon of grow big. Then add .5 teaspoons per gallon Kangaroots then .5 teaspoons per gallon micro brew. I mix then test ph and Ppm. It’s at this time I adjust ph.

I tend to go in the order in which fox farms lists them. I added nothing else this round except those items but did put in 1 teaspoon of cal-mag 1-0-0 to each bucket as well.

Is there a reason why a low volume 2.5 gallon of nutrient mixture is being supplied to the plants? The larger the volume of the nutrient reservoir the longer the nutrient mixture can remain pH stable. I would check and readjust the pH and PPM strength daily. Low volume nutrient reservoirs require frequent adjustment and replacement. I would replace the nutrient mixture every 5 - 7 days.

The starting source waters pH is too high and must be partially lowered and then the multiple bottled components added in specific order. The order of operation is improper and creating bound complex nutrient combinations the plant can not easily access. If any single nutrient or micro nutrient is present in too high concentration it causes the other ingredients in the nutrient solution to negatively react with each other and either form much more complex combination forms of nutrients, form into solid suspended or crystallized salts, or combinations which are harmful to the cannabis plants.

Plants grown under LED lights require additional calcium and magnesium.

While adding the nutrients if you use a calcium supplement the calcium supplement must be added first to the water.

If using a calcium supplement in hydroponics do not allow the pH to rise above 6.3 otherwise the calcium will precipitate to a solid in suspension and not be absorb able by the plant. For example if a calcium supplement is added to either water or nutrient solution above pH 6.3 80% of the calcium returns to a suspended solid or if total combined dissolved saturation level of all ingredients is exceeded will form calcium powder and drop out of solution nearly immediately. Cannabis plants are not able to directly use solid calcium forms. In a nutrient solution calcium must be kept between pH 5.6 and pH 6.3 to be in a form usable for the cannabis plants requirements.

Are you adding any micro nutrient to the nutrient solution?

These negative interaction are more complex if incompatible nutrient lines are used or pH is too high in improper range to allow the multiple part ingredients to exist in their intended forms most easily accessible for the cannabis plants requirements.

Always shake your nutrients before use.

Always add your nutrients to water not each other, when added to each other they react and drop out of solution in a form that plants can not absorb.

Between each addition thoroughly mix each additive into the nutrient solution and allow 2 minutes minimum of rest for the component to finalize the reaction and become stable within the nutrient solution.

Start with adjusting the water sources pH below pH 6.

Add the calcium supplement first.

Add the Microbe Brew

Add the Kangaroots

Add the Grow Big Hydroponic Liquid Plant Food additive to the nutrient solution.

Add the Big Bloom additive to the nutrient solution.

Mix the nutrients well into your solution.

the first few time that a new nutrient solution is replaced I would check and record the pH of the nutrient solution after each addition to maintain the pH in optimal range. This shall allow you to predict the amount of pH down required for the first initial source waters pH adjustment.

The municipal water supply that I use ranges from pH 7.2 - pH 7.7 seasonally and I must adjust water supply before adding any additive to the nutrient solution in order to prevent pH range nutrient lockouts which would otherwise occur as the nutrient mixture is created and render the mixture ineffective..

When mixing nutrients and adjusting the nutrient mixtures pH you must allow waiting time to approximately 12 - 20 minutes to allow the pH to balance after initial adjustment. the buffering effect of calcium excetera will first display a reading then pH buffer rebound shall change resultant pH of the mixture.

the order in which i adjust and add nutrients is

initial pH adjustment
If using a silica additive add to the nutrient solution before adding the calcium
Calcium supplement
Micro nutrients
Grow nutrients
Bloom nutrients
Possible other bloom enhancer
final pH adjustment

Please keep a notes for each nutrient mixture in a notepad with the order of the operation, what you are currently using and quantity in millilitres per gallon as a reference. The record will allow you to return back to a last known good order of operation in the event the cannabis plant begins presenting issues.


Here is FoxFarm's Customer Service/Product Support

Contact FoxFarm customer support with details of all products used for assistance or question they may refer to their chemists for qualified answers.

The add back method of pH and PPM management is to readjust the nutrients solution in the reservoir back to an optimal pH 5.8 by adding a calibrated pH adjusted water source is added to the nutrient reservoir to return the nutrient solution back to pH 5.8. This method reduces high PPM strength while allowing the nutrient solution to be used for longer periods before replacement is required.

 

[Terminatorkader]

I’m so glad This site saves info because all that is extremely useful. There’s so much info out there, you pick and choose what you think sounds right when you’re just starting a process and go from there. In reading and watching, I came across a few videos regarding Dwc stating to only use 2.5 gallons so there is an an air gap between the water and bottom of basket. The baskets I have are 8” wide and a bit deep. This is only my fourth grow. I have been changing my solution weekly. I do mix between each solution add. I check the reservoirs twice a day for adjustments because of the temp flux. My plants are not in the bucket when I make adjustments. I was referring to incorrect data (I.e.the chart online I had for ph). I had started out lower ph but then let it go a little higher based off that.

My first grow was an auto outdoors in soil. My second grow (and most successful) was an indoor tent grow in soil. My third grow journaled on here was a failure. I started out with bad soil and it went down hill from there. I decided to try hydroponics after doing two small nft systems for my vegetable garden. Dwc seemed a good way to go for this particular plant.

The plants otherwise look well. Minimal stem color change thankfully. I always watch the leaves. Are they drooping, bending,, clawing, twisting, etc. Some signs I know, some I still have to learn but the leaves now are outstretched and perky. So far no marks or discoloration on new growth. I see some leaves on bottom of the plant won’t make it but it will be minimal. They are in week four but I will veg them one extra week to recover a bit.

This morning as of 8 am back to 5.81 and 5.83

 

[KingJohnC]

An air gap is left between the nutrient mixture and pot lid bottom to stop nutrient over spray from being splashed out of the bucket from the agitation of the air stone. When you are able to figure out he maximum safe level of nutrients you may add without over spray mark the side of the bucket so that you are able to easily refill to the maximum safe nutrient level. Occasionally some beer and wine supply places also carry larger buckets than common 5 dry gallon 4.5 actual wet commonly encounter.

 

[Terminatorkader]

As the girls enter week 5, I just did a sump change. They’re looking good (except those leaves initially crispy from the ph issue) but it looks as though those changes did the trick

Thank you all!

 

[sativuhhh]

You can also get black 7 gallon buckets that are slightly deeper with the same tops. Can really help when the plants start getting really thirsty to have 2 extra gallons in there to keep things more stable.

 

[Terminatorkader]

Just want to thank you again they look so much better!

 

[KingJohnC]

I am happy that you have gained control over the hydroponic system and are managing the plants nutrient requirements, many people do not manage bucket systems very well. Check your local classified adds to see the failed grow equipment systems people purchase based on ethereal sales promises, any functioning system would never be sold for less that its weight in gold!

 

[KingJohnC]

When I fist began looking into growing cannabis to manage an otherwise untreatable medical condition I went to many grow stores and heard ethereal promises of anywhere from 1.6 - 2.2 grams per watt harvested if only i would purchase their $1600 bucket system and entire nutrient lines from only their store. Fairy dust! The classified adds were full of abandoned or failed systems, mostly either hydroponic or bucket systems which people could not manage to reach harvest with. I easily relate to many new cannabis growers difficulties and exasperation's they experience being relayed 50% - 50% misinformation and hype prevalent from those with financial interests tied to whichever miraculous new grow system is available. My first harvest was a failure or throat chocking harsh fertilizer damaged cannabis and not medicinal grade. It was a long and hard learning curve to figure out how to manage the cannabis plants requirements and grow medicinal grade cannabis.

 

[Terminatorkader]

It definitely has a learning curve. My set up for the hydroponic only cost me just under $200 (not including lights, tent… just for the hydroponic part) so I’m not overly invested but I’m a gardener. I love growing things so I really wanted to try the plants this way. They look besutiful and lush. Thanks to your advice dialing in ph and keeping tabs on Pom’s it already seems much better than soil for growing.

I have a decent size nft system I was experimenting with for greens prior. It’s such a great way to grow so far.

 

[Terminatorkader]

Omg seriously she looks perfect! Thanks to all of you. You’ve taught me a ton in s short period of time. I lost one to root rot. I’m sure the ph being severely off contributed but since getting that wrangled in, this one has just exploded! Almost perfect under your advice.

 

[KingJohnC]

You are welcome! I am happy that the cannabis plant is healthy, your cannabis plant is responding well to the environment you are providing. How many days of flower is the cannabis plant at? If in doubt add more pH adjusted water to reduce nutrient concentration strength and to correct nutrient mixture to 5.8 pH. I recommend conservative lower starting quantity of nutrients dosage and gradually increasing until full recommended dosage while monitoring the cannabis plants growth.

There are 2 separate markets within cannabis markets, producer grow operations and home medical cannabis or cannabis hobbyist grows. Many of the manufacturer recommended charts are for the grow operations when using much higher illumination levels or sell more bottles than needed for home usage levels. Cannabis plants can use high illumination and can produce increased growth, the equipment and electrical expense is quite costly. With a much larger area and upscale equipment large volume grows is the reason why that the feed charts begin with recommendations for rooted clones and not seedlings grown from seed. I recall when I first was invited to visit a grow operation and the larger grand scale lighting equipment and hydroponic system with control equipment was used which when set up properly with everything automated in order to produce high producer level yields.

 

[Terminatorkader]

She’s just started week8 (14 days into flower) Last sat with an estimated 7more weeks to go. On Saturday’s I change the water add nutrients then add 1/3 every other day after until next change. I check ph three times a day. I take it to 5.78 and let it drift up to 6 then bring it back down to 5.78. She seems to like it I think. I check first thing in the morning, at about 12:30 and then at 5pm. She’s drinking a gallon a day once I knew the actual ph to adjust to shexreally responded well. She’s a nice deep green. Slight purple on a few stems but it’s not all of them and not n the main stems.

One of the main stems broke off but I wired it right away to the main Otto growth and it took like a graft. It’s been two weeks after that and wilting. My nutrient schedule is in teaspoons per gallon. Sat she gets that dose them every other day it’s 1/3 that does. Her four sets of leaves since light change show no issues or burn it’s all a learning experience but I’ve been very happy with the results of hydroponics vs soul so far. I upgraded her from a 5 gallon pale to7 gallon pale. She’s scrogged so where she lays is where she stays for now. She’s getting crystals already snd on leaves too . Really good outcome.

 

[KingJohnC]

Very good, The way you are managing the small volume reservoir is very well. Please calibrate your pH and PPM meters weekly or better. Are you monitoring the PPM of the nutrient strength as well relative to the pH? Are you able to correlate how the daily decrease in PPM strength relates to pH rise? Is the amount of pH down required to lower the pH back to 5.8 pH consistent? Where did you locate the larger 7 gallon pales?