huge swing in pH, what could be causing this?

lorenzo08

Well-Known Member
Nope! Your calculation is absolutely right! This is why weak pharmacy grade (usually 3%) H2O2 isn't much use in a grow op.
ur smart. I wanna be like you when I grow up. lol. is there any reason why so much H2O2 is used? 95% or so oxygen saturation from an air stone sounds pretty good, does H2O2 raise that as close as possible to 100%? I understand it kills off bad bacteria, but wouldn't to much H2O2 kill off all bacteria, good and bad? my thinking, have just enough H2O2 to always keep bad bacteria and algae at bay, but not much higher then that.
 

Al B. Fuct

once had a dog named
my thinking, have just enough H2O2 to always keep bad bacteria and algae at bay, but not much higher then that.
You're guessing. All bacteria, fungi & algae spores are equally susceptible to being oxygenated out of existence with equal amts of H2O2. You don't get your choice as to which ones you annihilate.

There's no such thing as beneficial bacteria in a standard hydro op. You're growing ONE organism- cannabis plants. Anything else is on the murder list.

50% H2O2 @ 1ml/L is actually a very low dose, but high enough to prevent any pathogen growth. Most sellers of H2O2 recommend 10-25ml/L.

95% or so oxygen saturation from an air stone sounds pretty good, does H2O2 raise that as close as possible to 100%?
Who gave you those figures? Your guesses again?
 

lorenzo08

Well-Known Member
50% H2O2 @ 1ml/L is actually a very low dose, but high enough to prevent any pathogen growth. Most sellers of H2O2 recommend 10-25ml/L.
I've had good results so far, but it would be good to prevent a problem in my res before it starts. would you recommend I pay the extra money for the 50% H2O2 and shoot for 1ml/L, or just continue with what has been working for me?
 

Al B. Fuct

once had a dog named
I've had good results so far, but it would be good to prevent a problem in my res before it starts. would you recommend I pay the extra money for the 50% H2O2 and shoot for 1ml/L, or just continue with what has been working for me?
I think you'll save money using the proper, high strength stuff. Let's say that the 3% stuff is about $3 for a 250ml bottle. Just 3% of that 250ml is H2O2 (7.5ml pure H202, the rest is water), so at that $3/250ml rate, you're paying 40c per ml of pure H2O2. I buy 50% grade H2O2 for $5/litre. 500ml per litre is pure H2O2, so each ml of pure H2O2 costs me $0.01 (yes, 1 cent).

us noobs are good at guessing. I'm sorry! :eyesmoke:

ask me anything about computers or anything electrical and I wont be guessing.
Apply the same logic you do in troubleshooting. You wouldn't arbitrarily ground pin 268 of your computer's CPU IC just to find out what happens without first consulting the pinout diagram, would you? No, of course not. Research and know instead of jumping in blind.
 

corral hollow kid

Well-Known Member
Make friends with the metric system! It's much much easier to use litres and millilitres than gallons & ounces. The teaspoon measure is OK for cooking but is not standardised worldwide and varies even between the US, UK & Australia. Missing from the imperial system is a convenient and accurate small measure. 1 ml is 0.0338140227 US fluid ounces... see what I mean?
I see. I'll be going by the garden supply store tomorrow to get metric measuring stuff...and 50% H2O2.

My nutrient tank is all cloudy and the pH keeps rising. I need to do pathogen control ASAP!!!

Thanks Al!
 

Al B. Fuct

once had a dog named
yep, do a 1-time shock treatment with about 5ml/L 50% grade. You'll have a big pathogen load to react the H2O2 with. Follow that with 1ml/L every 3-4 days.

If your shop only has 35%, use 1.7ml/L.
 

born2killspam

Well-Known Member
I think you'll save money using the proper, high strength stuff. Let's say that the 3% stuff is about $3 for a 250ml bottle. Just 3% of that 250ml is H2O2 (7.5ml pure H202, the rest is water), so at that $3/250ml rate, you're paying 40c per ml of pure H2O2. I buy 50% grade H2O2 for $5/litre. 500ml per litre is pure H2O2, so each ml of pure H2O2 costs me $0.01 (yes, 1 cent).



Apply the same logic you do in troubleshooting. You wouldn't arbitrarily ground pin 268 of your computer's CPU IC just to find out what happens without first consulting the pinout diagram, would you? No, of course not. Research and know instead of jumping in blind.
Another good reason to go with stronger H2O2 is stability.. H2O2 reacts with water, forming water and oxygen (which really doesn't like to stay dissolved by itself beyond about 10ppm).. The more water in the mix, the faster this occurs.. After any given amount of time in storage, 50% H2O2 will be much closer to 50% than 3% or even 10% will be to their quoted concentrations..
Oh, and oxygen can travel pretty easily through the wall of a plastic bottle, so thats why there doesn't seem to be a pressure buildup in the bottle..

Edit: BTW I've done alot of playing around with old cpu's like that.. Believe it or not, randomly grounding pins very rarely does permanent damage, just freezes the thing up..:)
 

fitzyno1

Well-Known Member
Al b. wait til you here this.
I have H202 at 17% which i purchase on Ebay (i add 3 ml/L).
So on your last post here i decided to ring my local garden store to see if i could get some 50% grade. I rang them and a woman answered, i asked do they sell H202. She asked what is it, i said its hydrogen peroxide. She still didn't know and asked what's it for. I told her it's to give extra oxygen to the roots and for pathogen control to kill algae. She never heard of it, and asked how is it applied. I explained that you add it to the nutrients in a hydoponic system.
WHAT DO YOU THINK SHE ASKED NEXT? "whats a hydroponic system?"
I paused for a second, and asked her 'was she for real'. She then started to ask people in the back-round what a hydoponic system was. Half way through explaining what a hyroponic system was, i just had to hung up.
Now, is it no wonder why i always buy and deal through the internet for my gear.
 

lorenzo08

Well-Known Member
Al b. wait til you here this.
I have H202 at 17% which i purchase on Ebay (i add 3 ml/L).
So on your last post here i decided to ring my local garden store to see if i could get some 50% grade. I rang them and a woman answered, i asked do they sell H202. She asked what is it, i said its hydrogen peroxide. She still didn't know and asked what's it for. I told her it's to give extra oxygen to the roots and for pathogen control to kill algae. She never heard of it, and asked how is it applied. I explained that you add it to the nutrients in a hydoponic system.
WHAT DO YOU THINK SHE ASKED NEXT? "whats a hydroponic system?"
I paused for a second, and asked her 'was she for real'. She then started to ask people in the back-round what a hydoponic system was. Half way through explaining what a hyroponic system was, i just had to hung up.
Now, is it no wonder why i always buy and deal through the internet for my gear.

haha.. sounds like you had a wrong number. I get it, garden store doesn't know what hydroponics is. did you ask them if they know how to grow drugs? maybe they didn't know it's a plant. people who work at garden stores are stuck in the past, growing only in dirt. they don't know how to try new ways of doing things. I got some nice tasty veggies from my hydroponics. I've thought about growing in dirt outside, but all the dirt and bugs.. ew
 

born2killspam

Well-Known Member
Ppl who merely follow recipes annoy me.. I really hate the attitude that if something isn't common practise its just plain wrong, and the world of horticulture is teeming with ppl like that..
One lady at one of those places thought phosphoric acid would burn plant roots to a crisp.. I told her that I wasn't planning on gardening on a bad movie set where acids turn organic matter into smoking slime, but she was still adament that I would need aluminum sulfate.. It almost seemed like she was trying to force me to buy it.. She got really defensive when I asked why sulfuric acid is less harmful than phosphoric.. I mean that is the most famous of the face liquifying acids right?.:) I'm pretty sure she considers me roughly as ignorant as I consider her..
 

Al B. Fuct

once had a dog named
Oh, and oxygen can travel pretty easily through the wall of a plastic bottle, so thats why there doesn't seem to be a pressure buildup in the bottle..
Um, no. A common plastic bottle will hold O2 under a little pressure, no problem at all.

H2O2 bottles have vented lids, accounting for why they don't go pfffffffff when you open them.

Ppl who merely follow recipes annoy me..
Depends on the recipe.

I really hate the attitude that if something isn't common practise its just plain wrong, and the world of horticulture is teeming with ppl like that..
The world of general horticulture is one thing, the world of hydroponics specialists is quite another for the most part.

Cannabis growing has its very own set of 'popular' practises (especially after the advent of cannabis discussion forums, where wives' tales spread faster than anywhere) that are based in rumour & Chinese whispers. I fight those every day on here.

One lady at one of those places thought phosphoric acid would burn plant roots to a crisp.
Pretty obviously, this chickie didn't know shit about hydroponics or general chemistry. You clearly don't have much use for folks like that.
 

born2killspam

Well-Known Member
I guess its the fact that alot of ppl never consider the purpose of recipe ingredients that annoys me..
And LDPE is pretty permeable to oxygen.. It diffuses more than 200cc*cm/m^2 O2 per day at STP.. Just because something can build up pressure doesn't mean it isn't permeable.. LDPE is for more permeable to CO2, but if I mess up the air-lock when fermenting in an LDPE vessel, the CO2 will blow the lid right off..
 

Al B. Fuct

once had a dog named











Don't know what standards are applied in your area (or whether your H2O2 has been repacked post mfg) but H2O2 50% is an S6 Hazardous Substance in Aus and must be packed in approved containers, which these are. "2" is HDPE.
 

tehpmd

Active Member
I know this thread is old, but the original poster was never given the correct reason for his ph swing. It was not algae as he thinks but rather the plant amp from cutting eddge solutions: http://www.cuttingedgesolutions.org/catalog/images/MasterBroch.pdf

"*NOTE* Plant Amp contains Organic Acids which cause a temporary low pH reading. Do Not Adjust pH up. The pH will
rise naturally as the plant uptakes the chelated calcium in one or two days."
 
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