Sudden problems? Water ph testing! Nutrient lockout? Advice needed :3

sailormoon

Member
Hey everyone,
My plants are about a month old now and I was experiencing a sudden onset of deficiency symptoms: Yellowing, necrosis, spots, stunted growth, etc.. They were doing fine and all of a sudden were showing some alarming symptoms :(
The soil I'm using consists of Humus, sphagnum moss, perlite, lime and I've been using schultz liquid plant food 10-15-10 at about 1/2-1/3 strength once a week (when watering).

A very helpful user on this site has been taking the time to evaluate my problem and said it is probably due to nutrient lock-out.
I just poured some ph 7.6 dechlorinated tap water and tested the run off.. It came to 6.0.
I am guessing this means my soil's ph is probably way too low if it is evening out to 6.0? I am using ph liquid test drops that I use for my aquarium.

It is possible the ph is even lower but i don't think the drops/results color sheet are calibrated to go to ph's that low.

I am not sure how to proceed and I'm a little confused with all this because it is my first grow and I am aware how proper ph is detrimental to plant health and nutrient uptake!
Any advice would be really helpful. Thanks a lot :)
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-sailormoon
 

cannabineer

Ursus marijanus
How much and what sort of lime? That is usually a good pH-control agent, especially in peat-based soils.

But the other thing I'm noticing is that you're using an ordinary 10-15-10. Imo that's not enough K, and your symptoms line up with K deficiency. I would also consider adding Mg and S, nutrients weed loves and are not supplied by the plant food. Epsom salt 1 gram per liter will provide a drench yielding 100 ppm Mg.

But the two "action items" i suggest are dealing with what looks like overwatering ... and a fairly serious K deficiency. Free advice, and quite worth it! ;) cn
 

sailormoon

Member
Hey, thank you so much for the advice :)

I contacted the company about what sort of lime and how much they use and never got an answer unfortunately.
I will pick up a higher quality fertilizer containing micro nutrients and give that a shot.

I am not sure if I am over watering because I usually water once a week or basically whenever I notice the top 1-2" are dry.

What do you think about my runoff results? I find those quite alarming (for the water in of 7.6 to come out 6.0..)

Thanks again :)
 

jpeg666

Well-Known Member
How much and what sort of lime? That is usually a good pH-control agent, especially in peat-based soils.

But the other thing I'm noticing is that you're using an ordinary 10-15-10. Imo that's not enough K, and your symptoms line up with K deficiency. I would also consider adding Mg and S, nutrients weed loves and are not supplied by the plant food. Epsom salt 1 gram per liter will provide a drench yielding 100 ppm Mg.

But the two "action items" i suggest are dealing with what looks like overwatering ... and a fairly serious K deficiency. Free advice, and quite worth it! ;) cn
You really think it is just K deficiency? It looks like there is some salt build up too, almost every tip of every fan leaf is burnt, possibly salt build up and a PH issue locking out the Potassium?
 

jpeg666

Well-Known Member
Also she said her 7.6 tap water is coming out at 6.0 which means on the way through the soil it is picking up a lot of acidic elements, which I assume is from excessive salt build up.
 

cannabineer

Ursus marijanus
You really think it is just K deficiency? It looks like there is some salt build up too, almost every tip of every fan leaf is burnt, possibly salt build up and a PH issue locking out the Potassium?
That is very possible. Salt buildup and lockout ... however those three-numbers plant foods are generally low in outright salts. The N is typically provided as urea.
But I'm not arguing against very possible lockout. OP would have to report on runoff ppm.

Which brings me to the question of water quality. If there's sodium in the water, that could cause what we're seeing all on its own. ~shrug~ cn
 

jpeg666

Well-Known Member
Yea that was my very first suggestion to her was to get a meter and test the runoff cause I am suspecting some burn and lockout
 

jpeg666

Well-Known Member
I have no clue what is in the kits so I do not know if it will give you a broad reading of the TDS in the water
 

FilthyFletch

Mr I Can Do That For Half
Looks like you have nutrient salt build up and lockout. Your Nitrogen and more then likely your K are not getting absorbed. Your tap water is way to high in ph to begin with needs to be closer to 7 ph max so your run off is actually is showing high build ups. You need to flsuh with correct ph 7 water for next 2 or 3 waterings. The shultz is just bad bad stuff to use for this kinda grow. Youd be better off just using Miracle Grow moisture control soil with ph 7 water if thats all you can get. Hydro shops have much better soil for like $14 a bag of happy frog from fox farm.
 

jpeg666

Well-Known Member
Yea she can't get any of that stuff right now so we have to get her going with what she can get for right now
 

cannabineer

Ursus marijanus
You cannot read TDS using a wet kit. It's an electrochemical (conductivity) measurement. A TDS meter (instrument) is indicated. Sorry. cn
 

sailormoon

Member
Makes sense.
Unfortunately if I were to order a TDS meter online it would probably take 2-3 weeks to get here which might be too long for my plants considering their current state. Are there any alternatives for the time being?
 

sailormoon

Member
RIGHT!? I always thought to myself it would probably be super inaccurate considering that the water barely has time to make contact with the medium but everyone recommends it so I follow what experienced growers suggest :) .
 

cannabineer

Ursus marijanus
also, measuring runoff tells you nothing of use. Not sure why people always recommend that.
It does provide one key bit of info.
A high runoff TDS can only come from a large amount of ionic solubles in the soil.
It is those that interfere with root function and cause lockout.
Jmo. cn
 
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