Can I make my own "ph up" and "ph down"?

[Guest]

guys i gotta run off to work but lemme point out that since the water in the distilled or purified gallon has essentially zero alkaline elements, you'll very easily be able to drop the pH. of the 1 gallon down to 'way low' really easily, with just the tiniest smidgeon of acid, but the acid's ability to argue with alkaline elements in your tap water, or otherwise mineralized water, ( got some nutes &/or additives in it) does, in fact rely on the amount of acid in your gallon of made-up solution.....

just to remind ya, (so if you find that adding just the smallest touch of acid drops the pH. of a gallon of distilled way down, but it won't do the same to a gallon of water from a well or city tap, or someplace where theres a quantity of alkaline minerals in the water...)

you guys probably already thought about that, but sometimes peeps who aren't so familiar with managing water might not think of stuff that goes unspoken in a thread as folks talk

sorry to interrupt the train of thought, i'm out - off to work, later -

 

[The Dopest]

great info -KiNgMaKeR- thanks! hey my reasoning is like this. GH uses some sort of acid and they have to cut it with something and i assumed distilled water, therefore when i check the pH of GH down and get the reading of 1.39 or whatever it should be the same as my concoction, right? a gallon of GH pH Down has the same pH as a gallon of this solution, so when i add this to my reserve it should react the same way, right?


*awaiting KMs shift to be over*

 

[mace_ecam]

pH down for hydro: phosporic acid
pH up for hydro, potassiumhydroxide or potassiumsilicate

muratic acid will raise the EC more than lower the pH, can easily burn plants
sulfur is a nute, too, but plants won't cope with as much as P(phosporic acid) or N (nitric acid)
in the right dose, all of them would be ok, especially if you don't need much, like for RO water, for tap, were you would need more, its a different story tough...

the only problem with potassiumsilicate is that it will lockout nutes if used at the wrong pH range, but it also adds silicon, makes plants tougher.

Vinegar? Pro's use vinegar in salads, amateurs in hydro
Seriously, acetic acid is not stable enough to be considered.

the risk for playing around with strong acids/alkalines?
is it worth it?

personally for me: i've burned enough holes in my pants by just dilluting store bought pH down/up products, no need to risk even more.

for those who decide that it is worth it, here is a few posts by Avalokita, he had a thread on the old CW, explaining how to:

Water Hardness and Hydroponic pH Control
Water Hardness
Water is classed as hard or soft depending on the amount of calcium and magnesium salts (carbonates and bicarbonates) dissolved in it. The hardness of your water affects what nutrients you use, because soft water nutrients contain more calcium and magnesium then hard water nutrients, because these elements are lacking in soft tap water.

My cold tap water is hard and tests at E.C. 0.7., but I add a bucket of R.O. water to the nutrient tank as well and this drops the water to E.C. 0.5. This means that at a given E.C. the plants will have more nutrients, because of the smaller amount of other things dissolved in the water, and this makes the nutrients to calcium ratio better.

For the indication of hardness, pH is not as reliable as E.C., because the pH depends on what is dissolved in it. At the hydroponics shop I used to work at, we collected rain water, and a 50 L bin of it had an E.C. of 0.0, and a pH of 7.8, but it only took 3 drops of acid to lower it to pH 6. The harder the water is, the more acid it will take to lower the pH. I haven’t found consistent reliable advice to what the exact E.C. cut off point between hard water and soft water is, so my general scale is:



code:-------------------------------------------------------------------------------- Water Hardness Rating
E.C. 0.0 Reverse Osmosis and Distilled water
E.C. 0.1 - 0.3 Soft water
E.C. 0.4 - 0.5 Medium hard water
E.C. 0.6 - 0.7 Hard water
E.C. 0.8 + Extremely hard, and too hard to be used for growing--------------------------------------------------------------------------------


pH Research Motivation
When I went to buy another bottle of blended acid, I found that in keeping with the over-priced and over-hyped philosophy of the rest of the Hydrotops range, the price of a 500 mL bottle of Hydrotops blended acid has gone up to £14. So I decided to research hydroponics acids and then make my own. This document is the result of my research.

Commonly Used pH Control Chemicals
The main things used for pH control are nitric acid and phosphoric acid to lower the pH, and potassium hydroxide or potassium silicate to raise the pH. Phosphoric acid is not as strong as nitric acid, so loads of it is needed in very hard water areas to lower the pH. Commercial growers in hard water areas use nitric acid as too much phosphoric acid will interfere with the N-P-K ratio, and may cause iron to get locked up and precipitate out as iron phosphate. [1]

The best thing for raising the pH is potassium silicate which is found in Liquid Silicon and other similar products. It is better then normal pH Up which contains potassium hydroxide because it gives the plants extract silicon as well as the potassium, and this helps strengthen the cell walls in the plants.

Which pH Adjusters Not to Use
Vinegar, lemon juice, and baking soda have also been recommended by members of the organic crowd. But using these will cause problems, for example baking soda supplies too much sodium. I saw someone recommending sulphuric acid, but this will supply too much sulphur.

Nitric acid is perfectly natural; it’s created by fraction distillation of compressed air to get nitrogen, reacting this with hydrogen to get ammonia and then passing this at high temperatures through several metal mesh screens made from platinum and rhodium to oxidise the ammonia into nitrogen dioxide which then reacts with water to form nitric acid. [2] So nitric acid is essentially made from air and water. Currently the hydrogen gas is obtained from natural gas, but in the future when the price goes high enough the hydrogen will instead be made from splitting water to get hydrogen and oxygen gas.

Citric Acid
I found that citric acid once was used to chelate iron to keep it in nutrient solutions, and some growers use citric acid to lower the pH. But it should never be used like this because it will form a sludge in the container, this sludge will clog drip lines, and the plants can’t cope with this much citric acid. [3]

Citric acid is not a stable pH adjuster, and it will cause the pH to go out of range very quickly. The editor of the Growingedge.com says, “… it isn't a good idea to use citric acid to alter the pH of the solution. You should use specific "pH up" and "pH down" solutions that are available at hydroponic retailers.” [4]

The hydroponics industry probably comes second to the diet industry for selling products that are over-priced, ineffectual or downright dangerous, so it did not surprise me to find that Earth Juice Natural Down pH Adjuster is citric acid crystals. It’s great for home-brewing but not for horticultural pH adjustment.

Acid concentrations
Acids for use in a hydroponics system should be diluted down to about 20% acid and 80% R.O. or distilled water. Any stronger concentration makes exact dosing difficult, and it corrodes the rubber inside the measuring syringes too quickly. 20% acid solutions are perfect for adjusting tanks between 40 to 100 L, but for small amounts, a 5 – 10% solution is better because it is difficult to adjust the pH accurately if 1 drop of acid solution makes the pH rise more than 0.05 pH point. It is more economical to buy stronger acids and dilute them down.

Acids and Safety
Concentrated acids can be dangerous, and nitric acid can burn skin very rapidly. So you should always wear gloves and goggles when you handle them. Concentrated acids heat up in water, and adding water to a container of concentrated acid can cause the solution to boil and shoot acid solution into the air. Nitric acid is much more dangerous in this regard then phosphoric acid.

So to dilute acids safely, you should always slowly, and with much stirring, pour the acid into the container of water. Never pour water into a container of acid. Most acids sold in hydroponics shops are diluted down enough that this is not so much of a problem, but it is good practice to add the acid to the water, just in case it might splatter onto your hands. Even if you are careful, you will always get tiny splatters of the solution on your hands so gloves are essential, especially for handling 20% or stronger acid solutions.

Blended Acids
Plants use Nitrogen, Phosphorus, and Potassium, these are the major elements the plants use, and they need a good balance between them, this is called the N - P - K ratio. Nitric acid supplies the N, Phosphoric acid supplies P, and both Potassium hydroxide and Potassium silicate supplies K, although the Potassium silicate also supplies silicon.

I want to keep the N - P - K ratio balanced as much as possible, so I use a blended acid, and a blend of nitric and phosphoric acid is the best. Nitric acid is a stronger acid then phosphoric so it is better for growers in hard water areas, but as the plants use up the nitrogen, this causes the pH to change. Nutrient solutions that are pH adjusted with phosphoric acid are the most pH stable.

The Ideal Blended Acid


code:--------------------------------------------------------------------------------Water Hardness Acid Blend
E.C. 0.0 - 0.2 65% Phosphoric, 35% Nitric
E.C. 0.2 - 0.3 50% Phosphoric, 50% Nitric
E.C. 0.4 - 0.5 65% Nitric, 35% Phosphoric
E.C. 0.6 - 0.7 75% Nitric, 25% Phosphoric
E.C. 0.8 + Get yourself a Reverse Osmosis Unit--------------------------------------------------------------------------------


Making a Blended Acid Solution
Because the water I make up has an E.C. of 0.5, I have medium water hardness, and my ideal acid blend is a 20% acid, 80% R.O. water solution of which the acid part contains 65% nitric acid and 35% phosphoric acid. It’s created by calculating how much water is needed to dilute my nitric and phosphoric acids down to 20%. Then while wearing gloves and eye protectors pouring each acid into separate glass containers holding the exact amount of R.O. water needed. Then mixing 650 mL of the 20% nitric acid solution and 350 mL of the 20% phosphoric acid solution together.

Calculating Water and Acid Percentages to Make Up a Precise Acid Blend
Step 1: Desired volume of acid solution
= 650 mL (S1)
Step 2: Desired concentration as a percentage
= 20%, This is converted to the decimal by dividing it by 100% (P2)
Step 3: Calculate actual amount of acid in final solution
= (20%/100%) x 650 mL = 130 mL (S3)
Step 4: Establish the concentration of the acid solution in the bottle you bought as a percentage
= 24.5% (P4)
Step 5: Calculate what volume of bottled acid contains the desired amount from step 3
= [S3 x (100 – P4)]/P4
=> [130 mL x (100% -24.5%)]/24.5%
=> (130 mL x 75.5%)/24.5% = 401 mL
Step 6: Calculate how much water to pour the calculated amount of bottled acid from step 5 into
= S1 – S5 = 650 ml – 401 ml = 249 mL
Step 7: Clarify {S6 water + S5 of P4 acid makes S1 of P2 acid solution}
= 249 mL water + 401 ml of 24.5% acid solution makes 650 mL of 20% acid solution.

pH Changes During the Making up of a Nutrient Solution
When making up a nutrient solution, it is important to adjust the pH of the water before adding the nutrient. The nutrients will affect the pH, and it usually takes about 2 hours after adding the nutrients for the pH to stabilise, as all the buffers in the water have to come to chemical equilibrium. Having a bubbling stone in the solution mixes up the water and speeds this up. I found that if the pH rises somewhere above pH 7.5, then a white precipitate forms as calcium and possibly micronutrients lock up and precipitate out.

I used to always add 18 mL acid and the nutrient, and then add 5 mL of acid 45 minutes later, this gave me a pH of 5.8. But I was very surprised to find that when I added 23 mL of acid and the nutrient all at once to the tank it gave me a pH of 4. So I found that if all the acid is added at once, then this completely over-acidifies the nutrient solution, and the reason for this is the buffering action of the bicarbonates in the water breaks if the solution drops below pH 5.3. [5]

Maintaining the Correct pH Range with Different Nutrient Brands
The acidity of individual brands of nutrients varies, but with Growth Technology Ionic nutrients I adjust my water to between pH 5.5 and 6.0, then add the nutrients, and after a minimum of 45 minutes leaving the solution bubbling, I add more acid to drop the pH to 5.6, and then turn the pump on. I keep the nutrient solution between pH 5.6 and 5.8, and only add acid to adjust it if it rises above pH 5.8.

When I used to use Hydrotop’s Hydrolite nutrient, which was their most stable nutrient with extra buffers and micronutrients, I found that everyday in a 78 L tank the solution would drop out of the pH 5.6 to 6.0 range, I needed to use massive amounts of Liquid Silicon to raise the pH, and some days the pH would drop from pH 6.0 to pH 4.7 overnight. I no longer use Hydrotops nutrients, because they are not as pH stable as Growth Technology nutrients. But people should be aware, that depending on what brand of nutrient they are using, and after the initial tank pH adjustment, they might need to use a pH raising chemical rather then an acid to keep their pH in range. Green Haze nutrient is an extremely acidic nutrient that suits people in very hard water areas, so they might find that their pH drops too low if they adjust their water to pH 6.0 before adding the nutrient.

But as long as the nutrient solution stays between pH 5.5 and 7.5 until the buffers have finished stabilising, and the plants are fed with nutrient solution that stays between pH 5.6 and 6.0 (5.5 and 6.1 for lazy growers) then the plants will be happy with it.


quote:
--------------------------------------------------------------------------------
Quotes and Sources taken from the Web on 3 October 2004:
[1] When iron is supplied as an inorganic salt, such as FeSO4 or Fe(NO3)2, it can precipitate out of solution as iron hydroxide. If phosphate salts are present, insoluble iron phosphate will also form.
http://academic.sun.ac.za//natural/botany/mdc_web_material/essential elements/hydroponics.htm

[2] http://www.platinum.matthey.com/applications/chemical.html

[3] To prepare rock wool and to leach out the excess of nutrients during growth you could also use monohydrate citric acid (which is not the same as lemon juice!).
Citric acid is never to be used in combination with nutrient though (i.e. to lower pH), as it will form sludge in the container. Besides this slime clogging your (eventual) drip-system, your plants can't cope with these (protein) molecules.
http://www.wietmeneer.nl/growing/haze.html in Section 6. Hydroponics

[4] Q. I have also had a difficult time maintaining the proper pH. I use citric acid to correct it, but the next day it is usually up to 8 again.
A. … it isn't a good idea to use citric acid to alter the pH of the solution. You should use specific "pH up" and "pH down" solutions that are available at hydroponic retailers.
http://www.growingedge.com/community/archive/read.php3?c=GR&q=1245


[5] http://www.wietmeneer.nl/growing/haze.html in Section 6. Hydroponics

--------------------------------------------------------------------------------



Last edited by Avalokita on October 21st, 2004 at 04:21 AM

peace,

mace

 

[sproutco]

(using sulfuric acid) sulfur is a nute, too, but plants won't cope with as much as P(phosporic acid) or N (nitric acid)

Not true. Plants can tolerate alot of sulfur and you want really ever see any sort of toxicity. Adding nitrogen or phosphorus from these other acids might not be desirable if you already have enough of either.

 

[sproutco]

i aint skeeeeeered...

A true success story.

 

[Verite]

Not true. Plants can tolerate alot of sulfur and you want really ever see any sort of toxicity. Adding nitrogen or phosphorus from these other acids might not be desirable if you already have enough of either.

Not if you are using sulfur with every watering and feeding. Especially since sulfur is highly mobile in the soil unlike phosphates. Plants can tolerate some sulfur but not at the rates you are talking about.

Mobile in soil:
Nitrogen, Sulfur, Boron

Somewhat immobile in soil:
Potassium, Calcium, Magnesium

Very immobile in soil:
Phosphate, Iron, Manganese, Copper, Zinc

http://www.farmtested.com/56.html

 

[Haps]

It is very good to have this information, sometimes there is no hydro store, or ordering option. I like having a back up plan if my store bought runs out. Nix on the sulpher and muratic though, maybe in a short term pinch. I tried just using fulvic, it did not go down enough for my needs, but is marvelous stuff for the frosty ones. Maybe I just needed a better concentration.

Now, can you guys work up a list of rocks - stones - that the nutes come from, so I can just toss a net bag of rocks in my dwc res, and just add water?
H

 

[sproutco]

Highly mobile in the soil means it would leach out with repeated waterings. You would not be adding alot of sulfur. It takes 11 ounces 35 % sulfuric acid per 1000 gallons of water to neutralize 1 me/L alkalinity. 1 ounce in 1000 gallons is 1.14 ppm sulfur. So 11 x 1.14 = 12.54 ppm sulfur Common range is 50 ppm sulfur in nutrient solutions. Plants actually require as much sulfur as magnesium. A book to get at your local library is Water, media, and nutrition for greenhouse crops edited by David Reed isbn 1-883052-12-2 It goes into alot of detail on acidification of water. More than you really want to know. Fairly easy to understand as some of the math is worked out.

 

[Guest]

wow....

such hostility and trolling for a simple post talking about ph alternatives....

beyond me lol.

peace

and

It is very good to have this information, sometimes there is no hydro store, or ordering option. I like having a back up plan if my store bought runs out.

Good info man, this could happen and it's good to know, thanks for the info...

 

[Verite]

No, mobility isnt defined as 'gets leeched out with the watering', especially when its very common for indoor growers not to water to the point of flooding their growroom. Mobility in the soil has always referred to availability in the soil for the roots to pull up elements into the plant.

http://www.farmtested.com/56.html

 

[glock23]

hehe...I was looking at the title of this thread a little cross-eyed and I read it as "Can I smoke my own "ph up" and "ph down?"

 

[BluEBLaZeS]

a few drops of orange juice in water should ph down that
what i really want to try is mixing molasses in the soil. sweet sweet buds?

 

[Guest]

is that the way it works...blueblazes..ha..ha...ha

 

[Guest]

lol

 

[Guest]

The definition of "Hubris:"

The definition of "Hubris:"

I told Macster about two months ago, that battery acid won't conduct electricity, therefore won't show any E.C. change when you pour it into water.

Battery acid is the conducting fluid in a car battery, doh.

Sorry if they all died Mac.



B000ooooo, creepy forum membah... YaAAY, BEER....!

 

[simba]

this is from a catalog..

ph up Potassium hydroxied 4% solutions
ph down sulfuric acid 4% solutions
ph down Phosphoric acid 4% solution..
so i say that guy that started this was 100% correct any one saying other just doesnt know or fine with paying way more than something is worth..
great job thinking outside the box and bringing this thread to life..
i have been concidering making my own..

 

[simba]

i just ganked this from the MSDS on the genhydro.com site..

The percentage of mixture information for pH UpTM is withheld as a trade secret. The basic ingredients of
pH UpTM are potassium carbonate and potassium silicate.


The percentage of mixture information for pH DownTM is withheld as a trade secret. The basic ingredients
of pH DownTM are phosphoric acid, citric acid and mono ammonium phosphate.

 

[sproutco]

Thanks. You can grow some pretty plants with sulfuric acid and sodium hydroxide.

 

[Guest]

I've been using watered down battery acid as ph down for a couple of months now...and silica Blast for ph up. Both products are working perfect. No issues. I can't vouch for how stable they are in a rez...but in my buckets of nutes waiting to be used...it doesn't sway much from sitting. I don't use air stones either.

Thanks Sproutco.

Cheers,
SH

 

[aweman]

ph up

ph up

I was at work today.. working in the boiler room and found a chemical called
this came off the WHMIS sticker..
Series 5404 Quatic industries
Boiler Alkalinity adjuster & scale preventer
Sodium Hydroxide solution class 8(9.2) un1842 pks group 8

Now i have a small glass juice bottle half full.
I put 1 drop into 1.5L tapwater and it went up
Tapwater Ph 6.72 ec 301 ppm 150
one drop Ph 8.75 ec 334 ppm 167
checked with black hanna Ph/ec/ppm
You think this is safe in a recirc dwc system
I will be taking clones before anything
thanx and ttyl