DWC ppm?

BigBuddahCheese said:

Jesus 1500? I am with SS on this... my top ppm is NEVER over 1000 in flower and most time it's in the 700-800 range. Less is more in DWC, now my StinkBud aero rails I was in 1300range, but that's a different story then DWC.

You either have MONSTER plants in DWC or your nutes are pretty poor, unless the ppm is accounting for sweets and other non-nutrient for the plant.

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so whats up with my dwc system my ppm is running at 1000-1200 im using sensi bloom a&b and my tap water is about 350 how do i lower my ppm w/o having to buy water every time or buying a ro filter?

Use a BRITA filter or one of the charcoal filter faucet devices.

superstoner1 said:

ppm in dwc really needs to be a little lower due to the roots being submerged in the res and having constant availability. i never go above 1000 in aero and 600 in dwc.

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wish i would have read this before week 7 of my last grow!!! burned up my ladies quite nicely at 1000ppm

303blunt303 said:

so whats up with my dwc system my ppm is running at 1000-1200 im using sensi bloom a&b and my tap water is about 350 how do i lower my ppm w/o having to buy water every time or buying a ro filter?

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I could be wrong, but I think your nute ppm would be the number your meter shows minus 350. I've never been 100% clear on that point, but it makes sense. My tap water can be anywhere from 150-300 and my last grow consistently posted PPM numbers between 1100-1250 but I don't think I was over-feeding, which is why we look at the EC/PPM...to make sure we aren't over feeding causing nute burn.

ganiman said:

Damn, things went downhill quick in here.Lol!

Thanks for the info canna. I know this maybe apples to oranges type comparison, but many people in the saltwater aquarium world use a co2 scrubber(filtering air pump inlet air thru sodalime) to raise the ph a few tenths.To me that means carbonic acid can form even with no co2 enrichment. Just wondering what your thoughts are on this link

http://www.reefcentral.com/forums/showthread.php?t=2097651

TIA,
ganiman

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Sorry I missed your bumpity there!

Carbon dioxide in water is definitely in equilibrium with carbonic acid and bicarbonate. Reef aquaria are rather specialized environments, though. Coral in the wild lives in a superaerated environment, and I can see reef life being adapted to low aqueous CO2 levels, to a point where scrubbing input air for high-volume apps (protein skimmer) makes a difference. Since reef tank water is alkaline, it will have a concentrating effect on atmospheric CO2, with consequences for the water's chemistry.
You've sent me on an enjoyable goose chase through the 'Net; i have my evening's reading. I'm surprised by the utility of scrubbing reef tank air ... and it's starting to come together for me. I'm especially intrigued by how wild coral reefs maintain their alkalinity despite vigorous exchange with untreated air. i haven't found that answer yet ... but dire warnings about the impact of rising atm. CO2 levels.

But for freshwater hydro, the carbon dioxide level limits are much more lenient. And since nutrient is on the acidic side (compared to reef water which is not of pH the equilibrium will be pushed toward the carbonic (volatile) side. It will then diffuse out (faster with an airstone), which is why dropping the pH of hard water will have a hysteresis or "bounceback" effect in pH.

/tangent
cn

Hey thanks for the reply cn. Seems i got the right person to reply considering your knowledge on this subject,and Im glad you enjoyed the goose chase

My question ultimately is,"Would scrubbing co2 from the air pumps in a rdwc system be helpful,be harmfull ,or have no effect aside from maybe raising the ph a few tenths?"

And i think its more brackish hydro than fresh water hydro in my case using GH 3 part.


Thanks again for sharing your knowledge,
Ganiman

I would have to say it makes no difference, and adds a consumable for which you have to spend. And since you're not in alkaline seawater (which relies on the extreme alkaline end of bicarbonate's buffer range) but in nutrient (whose signature buffer, sesquibasic phosphate, is not volatile) I don't see atmospheric CO2, or even the 5x atmospheric used by the closed-room supplementers, as having a measurable effect on the broth's pH. cn

Thnx,

The cost/benefit was the deciding factor for the experiment and if there is no benefit,there will be no cost.I might still try this on a small scale instead of dedicating the whole crop due to the fact im hardwired as a tinkerer,which is how I often learn regardless of the outcome.

Your reply got me thinking that if the elevated co2 had no effect on the nute mix in a sealed growroom,then it would be a benefit to keep the air pumps in the room(where they are now) to take advantage of the elevated o2 levels that the plants provide.Does that theory hold water in your opinion?

Thanks again and enjoy your evening,
Ganiman

Will post my findings between the rdwc kids pumped with enriched co2 and the ones pumped with carbon scrubbed air

Ganiman

ganiman said:

Thnx,

The cost/benefit was the deciding factor for the experiment and if there is no benefit,there will be no cost.I might still try this on a small scale instead of dedicating the whole crop due to the fact im hardwired as a tinkerer,which is how I often learn regardless of the outcome.

Your reply got me thinking that if the elevated co2 had no effect on the nute mix in a sealed growroom,then it would be a benefit to keep the air pumps in the room(where they are now) to take advantage of the elevated o2 levels that the plants provide.Does that theory hold water in your opinion?

Thanks again and enjoy your evening,
Ganiman

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If you supplement an extra, say, 1000 ppm CO2, the most extra oxygen you'll get is 1000 ppm or 0.1%. On top of the remaining 21ish per cent, I see neither gain nor harm. For perspective, the difference in water's oxygen solvency for a single-degree change in (water) temp will have a greater effect. cn

I guess what I was getting at was that with all other variables being in the ideal parameters, it seems like the best place(based on the truths you've expressed) for air pumps to be is in the co2 enriched o2 slightly enriched g-room.

Yeah,sometimes i suk at expressing whats in my head into type. BTW,there should be a vaporizing emoticon

Thanks again,
Ganiman

http://youtu.be/dunKAwRN3P8

I'm new to DWC, got tired of dirt and guessing, etc. I have 2, 3-gal Rubbermaid tubs and switched to the Lucas formula Flora nutes after getting some burn with the 'standard' Flora formula.

My ppms are around 470 or so, roots look good so far. I'm about 3 wks into flower. 2 Widows in the front tank, 3 47's in the back. There are 3 in dirt that got burnt on the side (scrawny ones on the side, pls ignore). Am I ok so far ?

Thanks in advance !

roi said:

I'm new to DWC, got tired of dirt and guessing, etc. I have 2, 3-gal Rubbermaid tubs and using the Lucas formula Flora nutes. My ppms are around 470 or so, roots look good so far. I'm about 3 wks into flower. 2 Widows in the front tank, 3 47's in the back. There are 3 in dirt that got burnt on the side (scrawny ones on the side, pls ignore). Am I ok so far ? Thanks in advance !
View attachment 2376982View attachment 2376983View attachment 2376984

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If your @ 470 ppms with a calibrated ppm meter,your not doing the Lucas correctly

Gani

I just ran out of cal solution (bad, I know) so I'll get it pronto and check calibration. I mixed it according to the ratios, and ph'd @ around 5.8-6.0.


Thank you!

I use dutch master series , last run I burned my plants a bit with a 1000 ppm, stay around 700-800, u should be good

to whom it may concern this thread was very helpful as this is my first rdwc i have ever tried..... so thank you for asking the questions first
cheers

Trolls?