Using food grade H202 (35%) in hydro reservoir

graying.geek said:

Ca(ClO)3 has always been attractive due to it's general availability and low cost, but unlike peroxide, I don't know if I should be concerned with oxidation by-products that would build up with repeated application of Pool Shock.



I'd appreciate some detail regarding your grow space and protocol for Ca(ClO)3. How much, how often, the volume of your rez, and the area of your grow space? How often do you change your rez?



I get that your adding 50 ml of your stock soln to a 100 l rez every 3 days. Do you change your rez during your grow; if so, when?

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Yes i change my rez every 3 week, but i have to refill +-40l from mid flower every week.
But its not needed, i could just refill it every week or two during tue hole grow

Keeping a gal of 34% h2o2 in your grow room, in a plastic jug, seems to me, is about as safe as keeping a gal of gas in there. Spill it on some things, then you've got a fire... Then you realize what 34% h2o2 can really.do.. Not saying it isn't useful or fun to play with..

Renfro said:

My DWC system had two plants per row, six per room, with 6kW overhead and 3600 watts side lighting. System was auto topped off by RO filter. I had them in totes but when they were at peak my PPM's would drop by about 120 in a day. So I was always adding back nutes however without knowing what was being consumed more than other elements I played it safe and just changed them out. One could look at the plants and see whats lacking and replace that but I didn't wanna mess with that.

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Yeah, I'm aware that you're on a whole different level of growing, and I've relied on your experience frequently. My med+rec needs (~100 g/mo) are much more modest than yours, easily met by my 2'x4' grow space -- and I could probably do with half that -- so I can afford to use my materials more efficiently, potentially at the cost of a bit lower yield with a lot less trouble.

graying.geek said:

Yeah, ok. That explains it. Changing with that kind of frequency would go through nutrients like crazy.

My protocol for my 20-gal, 3-plant rez, has been 2 rez changes: the first at the beginning of flower and another midway through flower (although, I'm skeptical the second change is helpful to any significant degree) and then 50 ml of 35% H2O2 twice a week. But with the price of H2O2 rising I picked up a used, $60 1/10 hp chiller from CL, so I think I'll run that to keep the rez temp at 16.5'C - 18.0'C and pour in a bottle of 3% H2O2 at every rez change before nutes are added. Should keep me good.

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have you thought about a submersible UV light in your res?

rkymtnman said:

have you thought about a submersible UV light in your res?

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I have seen ones that are made to pump water through, inline installation.

Renfro said:

I have seen ones that are made to pump water through, inline installation.

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yep, i've seen both. they aren't very expensive either/

rkymtnman said:

have you thought about a submersible UV light in your res?

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Yup. I think I saw you suggest these in a post last year. Ran one in my rez for my spring 19 grow and it worked fine for contol of free floating fungi but algae would attached to the rez walls and the tank looked pretty green between rez changes. That's why I went back to dumping in 200 ml of the 3% H2O2 twice a week.

graying.geek said:

Yup. I think I saw you suggest these in a post last year. Ran one in my rez for my spring 19 grow and it worked fine for contol of free floating fungi but algae would attached to the rez walls and the tank looked pretty green between rez changes. That's why I went back to dumping in 200 ml of the 3% H2O2 twice a week.

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well, thanks for taking one for the team and trying it out. i would have thought it would have destroyed the algae too.

the other thing i looked at briefly was sodium percarbonate. dry form of peroxide basically. it breaks down into peroxide and soda ash. the soda ash was the part i wasn't sure how it would react to salt nutrients and the plants in general.

rkymtnman said:

well, thanks for taking one for the team and trying it out. i would have thought it would have destroyed the algae too.

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I expect it's due to the algae attaching more quickly to the sides of the rez as opposed to the Pythium that apparently remains free-floating for most of it's life cycle thereby getting pumped through the UV machine.

rkymtnman said:

the other thing i looked at briefly was sodium percarbonate. dry form of peroxide basically. it breaks down into peroxide and soda ash. the soda ash was the part i wasn't sure how it would react to salt nutrients and the plants in general.

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I expect that adding a significant amount of Na is going to be a problem, but @OldMedUser , can you pull out your chem degree and give us some input on using Na ₂H ₃CO ₆ in hydro?

graying.geek said:

I expect that adding a significant amount of Na is going to be a problem, but @OldMedUser , can you pull out your chem degree and give us some input on using Na ₂H ₃CO ₆ in hydro?

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i hated chemistry. but i did find this when looking up soda ash. probably not good for growing:


Sodium carbonate is used to soften water by removing Mg2+ and Ca2+. These ions form insoluble solid precipitates upon treatment with carbonate ions:
Ca2+ + CO32- → CaCO3

rkymtnman said:

i hated chemistry. but i did find this when looking up soda ash. probably not good for growing:


Sodium carbonate is used to soften water by removing Mg2+ and Ca2+. These ions form insoluble solid precipitates upon treatment with carbonate ions:
Ca2+ + CO32- → CaCO3

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Removing Mg and Ca won't be good. I know Na+ is required in trace amounts by most plants, but also toxic to most at relatively low levels.

rkymtnman said:

the other thing i looked at briefly was sodium percarbonate. dry form of peroxide basically. it breaks down into peroxide and soda ash. the soda ash was the part i wasn't sure how it would react to salt nutrients and the plants in general.

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It will raise EC to much from my experience. Tried it when I started my sterile routines. Easier to use calcium hypochlorite if you want to go sterile. It also has longer residual effect.

graying.geek said:

I expect that adding a significant amount of Na is going to be a problem, but @OldMedUser , can you pull out your chem degree and give us some input on using Na ₂H ₃CO ₆ in hydro?

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Just a diploma. lol

A one shot thing shouldn't hurt but too much sodium to use on a regular basis imo. Even at low levels blocks Ca etc so not worth the risk.

Someone mentioned starting a fire with strong peroxide but you have to be over 50% for that to be a real concern. Can rot a good hole in a wood floor tho.

I've been following @Heisenbeans for a while and last month he posted a vid of a UV sterilizer --> Sediment Filter --> Carbon (dechlor).. apparently before he put the UV in his sediment filter would be clear for a long time.. but just within a few days after adding UV it was all brown and narsty. I guess it depends on your water source but theres all kinds of shit in water, even municipal water with chlorine residual. The UV kills it and makes it more filterable. I haven't tried this yet but will soon. He also started using UC Roots vs bennies.. just food for thought it was interesting.

My ladies roots are 10x better now than they were.. but take a look at this guy's.. i can only dream of filling out a bucket like this.

infdjedi said:

The UV kills it and makes it more filterable.

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UV filters work best with a prefilter, like a sediment filter, this is because any particles in the water block the light, reducing the effectiveness.

So you should have, sediment filter -> uv filter -> RO filter or any other means of post filtration.

Also make sure you don't exceed the flow rate of your UV filter as the exposure time is compromised.

Most RO units come with a 5 micron pre-filter and we already filter our dugout water down to that so I want to go with 1 or 0.5 micron - carbon - RO - DI - then UV. The inline UV goes for around $250 on sale here at Canadian Tire and can handle way faster flow than what comes out of any household RO unit. If it cost me $1000 to set it all up it'll pay for itself in a year. Probably a lot less as I'll be needing lots more water once I have lots more plants. Cost us $20/week just for the RO we use for drinking etc.

Will h202 kill off the bacteria in hydroguard?