Splotchy yellowing of mid level leaf

[LearningMore]

This is an AK47 ILGM auto on day 39 above ground. It’s had a rough start as was in alkaline Kellogg soil that stunted it early. Currently in HF soil+30% perlite. Getting 1/4 strength trio (every third watering) plus got molasses and Microbe Brew several days ago. Was watered yesterday with only pH 6.5 filtered tap water plus 3ml CalMag per gallon (I have previously only given CalMag a couple times, at 2ml/gal). Yesterday was the first time I “watered to runoff”. Timing-wise, I’m going by pot weight, usually every 48hours (last week it went 72hrs once before it felt light). Under HLG600 at 24” and partial dimming (lux currently 29,000). Temps are 79-81 and humidity is around 65%. 24hr light. The close-up of the leaf is about mid-height on the plant. Trying to sort this before it becomes worse issue. Thanks.

 

[Proph]

This is an AK47 ILGM auto on day 39 above ground. It’s had a rough start as was in alkaline Kellogg soil that stunted it early. Currently in HF soil+30% perlite. Getting 1/4 strength trio (every third watering) plus got molasses and Microbe Brew several days ago. Was watered yesterday with only pH 6.5 filtered tap water plus 3ml CalMag per gallon (I have previously only given CalMag a couple times, at 2ml/gal). Yesterday was the first time I “watered to runoff”. Timing-wise, I’m going by pot weight, usually every 48hours (last week it went 72hrs once before it felt light). Under HLG600 at 24” and partial dimming (lux currently 29,000). Temps are 79-81 and humidity is around 65%. 24hr light. The close-up of the leaf is about mid-height on the plant. Trying to sort this before it becomes worse issue. Thanks.

Why the calmag? This looks like the start of a P or K issue.. Maybe both.. Could be caused by a few different things.. There are too many variables at play to try to pinpoint an exact cause.. But I'm leaning towards a ph lockout and or a nutrient lock out. 2-3 days is too long without watering.. Microbe life dies, nutrients become unavailable, and the ph rises as the pot dries out.. Soil should always be moist.

 

[LearningMore]

Why the calmag? This looks like the start of a P or K issue.. Maybe both.. Could be caused by a few different things.. There are too many variables at play to try to pinpoint an exact cause.. But I'm leaning towards a ph lockout and or a nutrient lock out. 2-3 days is too long without watering.. Microbe life dies, nutrients become unavailable, and the ph rises as the pot dries out.. Soil should always be moist.

If the topsoil is still damp (within a 1/4” of surface), and pot still feels heavy-ish, I wait (I’ll be honest: I check my girls 3-4 times a day). Generally at 48 hrs is when the top “knuckle” is dry and the pots are feeling lighter. I’m happy to water more often, but don’t want to be overdoing it.

I’ve read varying things about CalMag in soil, but it seemed that “most” people indicated that CalMag needs increase the second month, so that is why I added it (I do not do it every watering - more like every 4th-5th). Three days ago is the first time I added any Tiger Bloom, and started at just 1/4 tsp per gallon. Would you suggest eliminating CalMag and increasing the Bloom nutes to get more P/K?

 

[LearningMore]

So I researched P/K deficiencies, and I would say the up-close inspection looks more like P deficiency. Also, all of my waterings have been 6.4-6.5, but I just saw that P is best absorbed 6.5-7. Is my best plan to switch to the “big bloom” nutes which are 0-0.5-0.7 for now to get the P/K up, and give at pH 6.7ish?

 

[Proph]

If the topsoil is still damp (within a 1/4” of surface), and pot still feels heavy-ish, I wait (I’ll be honest: I check my girls 3-4 times a day). Generally at 48 hrs is when the top “knuckle” is dry and the pots are feeling lighter. I’m happy to water more often, but don’t want to be overdoing it.

I’ve read varying things about CalMag in soil, but it seemed that “most” people indicated that CalMag needs increase the second month, so that is why I added it (I do not do it every watering - more like every 4th-5th). Three days ago is the first time I added any Tiger Bloom, and started at just 1/4 tsp per gallon. Would you suggest eliminating CalMag and increasing the Bloom nutes to get more P/K?

There are a lot of variables at play.. What soil are you in? Depending on what type of pot you're using, it could be drying out from the bottom up. If so, a knuckle deep is way too late.. Growing plants, especially autos, is not something you can do by following a guide or set of instructions. No experienced grower uses calmag. It wasn't even around 5 years ago. The product is not just calcium, it's also magnesium.. They are two different secondary nutrients (which means you don't need much of it) that are completely different and can easily counter act each other. All nutrients must remain in a balance to work properly. Too much calcium will make magnesium and phosphorus unavailable for the plant to use.. Too much magnesium will make calcium and potassium unavailable for the plant to use. It's a delicate balance. You may say you only uses calmag here and there... But how much calcium and magnesium was already in your soil? How much was in the top dress? How much was released by the microbe life? Calcium is in almost everything.. You should be adding things when they are needed.. Not based on a calendar or a set of instructions. It's way too easy to get something out of balance. That's why people say "less is more". It's super easy to add a little of something when its needed. It's super hard to get something out if there is too much. Your situation isn't bad yet, but could get there if you are thinking that signs of deficiencies always mean to add something. Some deficiencies are caused by an excess of something (lock out).. It means that the nutrient is there and available, but the plant can't use it due to the excess of something else. The issues look exactly like a classic deficiency. So if your feeding and adding something every other watering, you know the nutrients are there.. That's when you should think about a possible lock out or excess of something. I would cut out the calmag and keep feeding the bottled nutes the way you are for a week and see how the plant responds. It's not in full flower yet so I would not increase the bloom nutes until it is.

 

[LearningMore]

There are a lot of variables at play.. What soil are you in? Depending on what type of pot you're using, it could be drying out from the bottom up. If so, a knuckle deep is way too late.. Growing plants, especially autos, is not something you can do by following a guide or set of instructions. No experienced grower uses calmag. It wasn't even around 5 years ago. The product is not just calcium, it's also magnesium.. They are two different secondary nutrients (which means you don't need much of it) that are completely different and can easily counter act each other. All nutrients must remain in a balance to work properly. Too much calcium will make magnesium and phosphorus unavailable for the plant to use.. Too much magnesium will make calcium and potassium unavailable for the plant to use. It's a delicate balance. You may say you only uses calmag here and there... But how much calcium and magnesium was already in your soil? How much was in the top dress? How much was released by the microbe life? Calcium is in almost everything.. You should be adding things when they are needed.. Not based on a calendar or a set of instructions. It's way too easy to get something out of balance. That's why people say "less is more". It's super easy to add a little of something when its needed. It's super hard to get something out if there is too much. Your situation isn't bad yet, but could get there if you are thinking that signs of deficiencies always mean to add something. Some deficiencies are caused by an excess of something (lock out).. It means that the nutrient is there and available, but the plant can't use it due to the excess of something else. The issues look exactly like a classic deficiency. So if your feeding and adding something every other watering, you know the nutrients are there.. That's when you should think about a possible lock out or excess of something. I would cut out the calmag and keep feeding the bottled nutes the way you are for a week and see how the plant responds. It's not in full flower yet so I would not increase the bloom nutes until it is.

I am now in Happy Frog soil (The last ten days or so).

I definitely learned from the initial bad soil how pH issues can mimic nute issues. I’ll put the calmag away and promise not to touch it! That certainly makes one thing simpler. My tap water is ~150ppm (filtered), not RO. Based on your detailed answer, I suspect the Ca yesterday tipped the plants further into a P deficiency that was perhaps already brewing.

I really appreciate your big-picture/conceptual answer. I am working to understand the “systems” and how my plants respond, and get away from “instructions” that are so limited in scope.

Moving forward: no calmag. I’ll water a bit more aggressively (watching for signs of overwatering to tell me if I overdo it). Water pH: would you advise sticking with 6.5? Should I vary the pH over a certain range (I’ve seen some say 6.3-6.7??)

Thank you!

 

[Proph]

It looks like you're in fabric pots.. It's really hard to over water a vegging plant in fabric pots. They dry out pretty quickly. Especially if there's a fan near by.. Fabric pots can also dry out from the bottom up or unevenly.. So a knuckle test isn't the best option to use with fabric pots. If you plan to keep microbe life alive, and nutrients circulating, the soil should always be moist. Most soil growers water daily using the 10% rule.. Which is 1 gallon of water for every 10 gallons of soil. So if you are in a 5 gallon pot, a half a gallon of water a day will keep it fully saturated without risk of over watering.

 

[LearningMore]

It looks like you're in fabric pots.. It's really hard to over water a vegging plant in fabric pots. They dry out pretty quickly. Especially if there's a fan near by.. Fabric pots can also dry out from the bottom up or unevenly.. So a knuckle test isn't the best option to use with fabric pots. If you plan to keep microbe life alive, and nutrients circulating, the soil should always be moist. Most soil growers water daily using the 10% rule.. Which is 1 gallon of water for every 10 gallons of soil. So if you are in a 5 gallon pot, a half a gallon of water a day will keep it fully saturated without risk of over watering.

Excellent. Thank you.