Testing soil ph is easy

[sproutco]

^^ ph 7 is probably too high especially if your mix is mostly soilless. In a soilless mix: phosphorus, iron, zinc, copper, manganese, and boron become less available when the ph gets high.

 

[inc0gnit0]

actually...... I just tested my pH(something i usually don't worry about). The girls are at about 1 week flower. The pH was about 6.8 when the composting was done and this seemed to keep them very healthy and growing faster than i could keep up with during veg. Now after being re-potted for the last time I just checked the pH and guess what? It's about 6.5. They seem to be growing very well so WTF?... Sproutco, I assume there is a reason you've been around so long, Thanks for the eyeopener.

My mix consists of :
Pro-Mix BX
D. Lime
gypsum
Epsom salt
Bone and Blood Meal

I initially wet this with water infused w\molasses
@ 1tsp to a gallon and let it sit for a week or two.

Mostly used Fish Emulsion for veg
but have been using a guano tea brewed for 24 w\molasses
for flower.

I'm sure I could be doing better, They seem to love me for it so far.

 

[sproutco]

^^ Thats cool your using gypsum and epsom salts. Not only does that supply calcium and magnesium but also sulfur. Check out my new thread in my signature about the importance of sulfur. Bet you didn't know plants require as much sulfur as phosphorus to grow normally. Good luck growing!

 

[Eazyman]

So....Is a "Soil" PH test strip different than a regular (pool store) PH strip?
i'm not only confused, I'm really high too! So.....can i test the runoff with a "generic" PH test strip,thats not specifically for soil??

 

[sproutco]

^^ Yes. Any ph strips will work. You may want to find one in range that you are growing in. Ph strips that test something like 4-7 could at least give you an idea of where your at. Better to save up and buy a meter.

 

[inc0gnit0]

Here they are.

This is the only one that's in the ground. I secured it to a piece of chicken wire to
maintain a low profile. Some non-compliant appendages still need some taming but I'll
do that later. Other than a few yellow lower leaves she's doing well. pH = 7.0



This is my fatest girl. She lives in my soilless mix and at this point her pH = about 6.5. This has been one of the best growing plants I've had. She lives in an
8 gallon pot and you cant really see her size in the pic. Should've used
a reference.





Now this one is my favorite. I've noticed some lower leaves with yellow patches that surround small brown spots. Possible Manganese def? She's in
my soilless mix and the pH is about 6.5. I'm sure the guano tea i use has done much for lowereing the pH and maybe this is a problem that started due to
a pH of 7.0. I'll keep my eyes open and see if it gets better since it's lower now.




This one is a clone taken from The plant in pic #2 Same soilless mix, pH is a bit closer
to 7.0 at this point.




Now for my problem child. This little gem is from the same seed as all the others, save my favorite plant (pic#3), but it's been a harder road for her.
Originally in the ground I've had a pH problem of 5.5 from early on. You can see she's begging for N. Look at the floweres.... She seems to be a week or
so ahead of the others. I couldn't get her to take in N in the ground so
I carefully dug her up and planted her in my mix. It's been a week since the
transplant and she is actually starting to get better. I don't know what the pH is now... perhaps I should check it... lol. Any idea wht the buds are so much more mature than the rest?

 

[Nape]

I have 10 WW started and I have a Q on PH.

Is this mix considered soilless mix for PH purposes?

60% SuperSoil Potting mix.
20% Vermiculite
20% Perlite

Should PH be 5.8-6.2 or 6.2-7.0?

Thanks,

 

[sproutco]

You can grow at a higher ph but you should make sure your micronutrients are chelated with something like edta. Above 6.5 ph alot of the micros even chelated ones begin to precipitate and become insoluble. Manganese deficiency would show up in the new growth first. It is immobile in the plant and when there is a shortage it can't move from lower growth/leaves to the top. Other nutrients also behave this way. See chart below. High ph usually will manifest itself by having top growth yellowish and not so dark green. This because of micros not being available like iron. Something affecting bottom leaves is a shortage of mobile elements. They can move to newer growth at the top and leave the bottom leaves deficient. See chart.

 

[inc0gnit0]

Maybe that's why my newest growth is always a lighter green, It looks much worse in the pics but it evens out as the plan grows. I'll try to get the pH down and see what happens.

 

[sproutco]

I have 10 WW started and I have a Q on PH.

Is this mix considered soilless mix for PH purposes?

60% SuperSoil Potting mix.
20% Vermiculite
20% Perlite

Should PH be 5.8-6.2 or 6.2-7.0?

Thanks,

What is in supersoil? If it contains alot of bark, like alot of these mixes have as filler, then it is considered soilless. Other additives like peatmoss are also considered soilless. A higher ph is used typically in mineral soils outdoors with a range of maybe 5.8 to 6.5 A ph of of 6 will work in soil, soilless, and hydroponics. It is kind of an all purpose number.

 

[sproutco]

Maybe that's why my newest growth is always a lighter green, It looks much worse in the pics but it evens out as the plan grows. I'll try to get the pH down and see what happens.

Sounds like the ph is high. Maybe lack of iron. Don't go applying iron though cause you will throw the balance of all your other micros out of whack. Too much iron = manganese deficiency possibly. Better to tinker with the ph. Don't forget to include some sulfur in your ferts. This could also give an overall yellowish color. It is also immobile and will affect your top leaves. Check out the thread in my signature on sulfur and ways to make sure you can include some.
Small brown spots on lower leaves could be a fungus leaf spot. Get a close up and post it in the cannabis infirmary. I have had plants loose half their leaves to fungus spots.

 

[inc0gnit0]

It seems as though the guano tea Ive been using for about 2 weeks acidic. If the tea pH's out at around 5 and my mix is about 6.5, Is it safe to say that I'm lowering it slowly every time i feed? Despite a few glitches here and there they are really packing on the flowers and other wise seem quite happy.

 

[Dr Dog]

Hey guys(girls?), after reading this thread I thought I should go and look to see what I had the girls buried in. Pro mix it would be, and it says it has lime in it. I was experiencing what I thought was lock out with a few of my plants developing yellowing edges on the fan leaves. My question is, since i really watered them heavy teh last time and added 1/3 nutes, should I be concerned at 5 weeks flower?

 

[Guest]

Theres not a lot you can do at this point,2 tbls dolomite lime per gallon promiox next time and you will see a big difference.If you have a way to check soil ph do it,I bet its around five or below.I wouldnt suggest watering in hydrated lime at this point,that stuff is really scary anyway,use too much and your dead

 

[vonforne]

Good thread Sproutco. If I may suggest, You could start the "Sproutco Infirmary" thread.You are informative in the forgotten elements. The things I have read this grow from you have helped to improve my garden....Thanks. Mostly about sulfur. I have been using the K-mag and a little gypsum. I really like the K-mag. Too bad they didn't send bigger samples. But a little goes a long way. If all of you have not used this instead of Epson salts....you should. just go to the website and they will send you your samples.Great stuff.......Thanks again Sprout for the great advise you pass around. I'm glad you decided to start your won thread. It will help many to improve their gardens as it has done for me.

 

[the cult]

i got a question for someone with good knowledge of ph and buffers, so i figured id take my shot here in this thread.

when i mix nutes and add ph down i take a reading with my metre, says eg 5.5 (approx where i want to be), im happy, i leave water for 30 mins, its risen to lets say 6.2, the effect of buffers in the nute solutions. i then add a drop of ph down, and take a new reading, its all of a sudden down at 4 something. how can this be? i dont understand the process. the buffering doesnt really change the ph of the water? it appears the ph was still at 5.5 as just a drop into the solution deals a total coupe de grace to the mix and i have to add fresh water in steps to get back up to the level i want to achieve.

can anybody explain how this works and what the buffers actually do?

and yeah, i calibrate my metre every week hehe

 

[Guest]

I have never checked EC or TDS before. Just the PH. What range should the EC and TDS be at in soil and soiless mixes?

 

[sproutco]

i got a question for someone with good knowledge of ph and buffers, so i figured id take my shot here in this thread.

when i mix nutes and add ph down i take a reading with my metre, says eg 5.5 (approx where i want to be), im happy, i leave water for 30 mins, its risen to lets say 6.2, the effect of buffers in the nute solutions. i then add a drop of ph down, and take a new reading, its all of a sudden down at 4 something. how can this be? i dont understand the process. the buffering doesnt really change the ph of the water? it appears the ph was still at 5.5 as just a drop into the solution deals a total coupe de grace to the mix and i have to add fresh water in steps to get back up to the level i want to achieve.

can anybody explain how this works and what the buffers actually do?

and yeah, i calibrate my metre every week hehe

Once the buffers are gone from the nutrient solution and its sitting at a certain ph, you might find that just a drop of ph down drastically will change the ph.

Titration
From Wikipedia, the free encyclopedia

Titration setup: the titrant drops from the burette into the analyte solution in the flask. An indicator present then changes color at the endpoint.Titration is a standard laboratory method of quantitative/chemical analysis which can be used to determine the concentration of a known reactant. Because volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant, of known concentration (a standard solution) and volume is used to react with a measured quantity of reactant (Analyte). Using a calibrated burette to add the titrant, it is possible to determine the exact amount that has been consumed when the endpoint is reached. The endpoint is the point at which the titration is stopped. This is classically a point at which the number of moles of titrant is equal to the number of moles of analyte, or some multiple thereof (as in di- or tri- protic acids). In the classic strong acid-strong base titration the endpoint of a titration is when the pH of the reactant is just about equal to 7, and often when the solution permanently changes color due to an indicator. There are however many different types of titrations (see below).

Many methods can be used to indicate the endpoint of a reaction; titrations often use visual indicators (the reactant mixture changes colour). In simple acid-base titrations a pH indicator may be used, such as phenolphthalein, which turns (and stays) pink when a certain pH is reached or exceeded. Methyl orange can also be used, which is red in acids and yellow in alkalis.

Not every titration requires an indicator. In some cases, either the reactants or the products are strongly coloured and can serve as the "indicator". For example, an oxidation-reduction titration using potassium permanganate (pink/purple) as the titrant does not require an indicator. When the titrant is reduced, it turns colourless. After the equivalence point, there is excess titrant present. The equivalence point is identified from the first faint pink colour that persists in the solution being titrated.

Due to the logarithmic nature of the pH curve, the transitions are generally extremely sharp, and thus a single drop of titrant just before the endpoint can change the pH significantly — leading to an immediate colour change in the indicator. That said, there is a slight difference between the change in indicator color and the actual equivalence point of the titration. This error is referred to as an indicator error, and it is indeterminate.

http://en.wikipedia.org/wiki/Titration

 

[Guest]

i got a question for someone with good knowledge of ph and buffers, so i figured id take my shot here in this thread.

when i mix nutes and add ph down i take a reading with my metre, says eg 5.5 (approx where i want to be), im happy, i leave water for 30 mins, its risen to lets say 6.2, the effect of buffers in the nute solutions. i then add a drop of ph down, and take a new reading, its all of a sudden down at 4 something. how can this be? i dont understand the process. the buffering doesnt really change the ph of the water? it appears the ph was still at 5.5 as just a drop into the solution deals a total coupe de grace to the mix and i have to add fresh water in steps to get back up to the level i want to achieve.

can anybody explain how this works and what the buffers actually do?

and yeah, i calibrate my metre every week hehe

I also make it a good habit to turn my meter off, and shake it so the electrodes get clear...than take my reading. Seems more percise this way.

Cheers,
SH

 

[minds_I]

Hello all,

Can those pH meters be used in sticny dirty slimmy bubbled tea with accuracy?

minds_I