The facts about CO2 ppm: don't use 1,500!

spurr · Oct 10, 2011

Wow! Thanks SO much for that! Really that was an awesome and very, very helpful post.

Now people can use the correct CO2 range, not BS claim of 1,500 ppm, via CO2 controller for < ~$300. Talk about awesome! Otherwise people will have to pay ~$800-1,000 for the same capabilities that Player2 was kind enough to detail here.

You just jumped to the front of my list of favorite new members

Your warranty was voided by just thinking about doing this

and so true.

Phillthy · Oct 10, 2011

i dropped my ppm down to 1000 to see if there is any effect. been running at 1500 for years.

spurr · Oct 10, 2011

Hey buddy,

Cool. Let us know what you think. What is the ppm at night?

Phillthy · Oct 10, 2011

dunno... co2 shuts down w lights out.

Agent-Smith · Oct 11, 2011

Great post!

headees · Oct 11, 2011

Player2 said:
Thanks to Spurr we all now have another good adjustable CO2 controller option.

The "hack" is simple, just jumper settings, but the instructions provided by support are incorrect. I sent a revision back to them so hopefully this error has been fixed for the next person who asks.

So, the correct jumper settings are;
J1-disconnect;J2-disconnect CO2≤700ppm,the relay turns on, CO2 ≥900ppm,the relay turns off

J1-disconnect; J2-connect CO2≤900ppm, the relay turns on；CO2 ≥1100ppm,the relay turns off

J1-connect; J2-disconnect CO2≤1100ppm, the relay turns on；CO2≥ 1300ppm,the relay turns off

J1-connect; J2-connect CO2≤1300ppm, the relay turns on；CO2 ≥1500ppm,the relay turns off

Factory jumper settings

Jumpers modified for 900 to 1100ppm CO2(J1 is parked, could be completely removed if one could keep from losing it.)

If you are sent the instructions stating J4 and J5, do not use the header on the daughter board. The instructions above are correct. Daughterboard header 9 and 10 shorted for 10 seconds will reset the calibration of the CO2 module, although you probably shouldn't be messing with it. Do it outside and don't breathe on it if you do.

Your warranty was voided by just thinking about doing this

Wow great post. Ive got the Digigro 'CoCo' controller, which does the same thing, activates at 1200 and shuts off at 1500. I wonder if it is 'hackable' as well. Ive already contacted digigro and asked if therewas some way to re-calibrate it at a lower interval setting and they said no, but of course they offered to sell me another model that you can adjust the ppms.

hashcat88 · Oct 11, 2011

I am wondering the same thing about the CAP PPM4. another preset unit which is set at 1450.

I took mine apart but am no electrician so was immediately confused. However hopefully someone can chime in...or maybe Ill just email CAP and hopefully theyll be cool and share the info.

habeeb · Oct 11, 2011

I would like to add,

when you mentioned to keep 500ppm or below, a long time ago

I achieve this by adding a timer to my Co2 controller. it takes a couple look in's at night to see where your at, and adjust. but it works at keeping a sealed room, sealed and good at night, and not running risk of going over 500ppm for night time..

thanks spurr. come back also...

also quick question, is it fine to keep temps low when running Co2 ( if your running hydro ) temp is more important then hitting a air temp mark for your Co2.. ???

also another, you say to run gas all through the grow? I thought it was believed to turn off a couple weeks before harvest? any info on that why we should run gas up to harvest?

spurr · Oct 11, 2011

Phillthy said:
dunno... co2 shuts down w lights out.

I only ask because If CO2 is much over 400 or 500 ppm at night, for extended periods of time, the plants may be hindered.

spurr · Oct 11, 2011

headees said:
Wow great post. Ive got the Digigro 'CoCo' controller, which does the same thing, activates at 1200 and shuts off at 1500. I wonder if it is 'hackable' as well. Ive already contacted digigro and asked if therewas some way to re-calibrate it at a lower interval setting and they said no, but of course they offered to sell me another model that you can adjust the ppms.

I agree, that was a great and helpful post by Player2. And I bet if you posted pictures of the 'guts' of your controller people here may be able to help you. I assume Digigro is not being honest, and you can adjust their controller. It sounds like they are trying to force you to buy a new controller by not telling you the truth. But I could be wrong ...

spurr · Oct 11, 2011

hashcat88 said:
I am wondering the same thing about the CAP PPM4. another preset unit which is set at 1450.

I took mine apart but am no electrician so was immediately confused. However hopefully someone can chime in...or maybe Ill just email CAP and hopefully theyll be cool and share the info.

What is the 'on' and 'off' set-points? Or is it 'on' anytime ppm is < 1450? According to Sam the Caveman on page 4, that unit is for CO2 burners. I'm unsure if it's also for compressed CO2 tanks.

If you post pictures of the 'guts' some people here may be able to help you.

spurr · Oct 11, 2011

habeeb said:
I would like to add,

when you mentioned to keep 500ppm or below, a long time ago

I achieve this by adding a timer to my Co2 controller. it takes a couple look in's at night to see where your at, and adjust. but it works at keeping a sealed room, sealed and good at night, and not running risk of going over 500ppm for night time..

Great advice :tiphat:

habeeb said:
thanks spurr. come back also...

also quick question, is it fine to keep temps low when running Co2 ( if your running hydro ) temp is more important then hitting a air temp mark for your Co2.. ???

I'm sorry, I do not fully understand what you're asking. Do you mean room temp vs canopy temp?

habeeb said:
also another, you say to run gas all through the grow? I thought it was believed to turn off a couple weeks before harvest? any info on that why we should run gas up to harvest?

I don't have any data wrt using CO2 until harvest, only personal experience. Which tells me it's not necessary to reduce CO2. However, other experienced folks like DesertSquirrel found if he kept CO2 at 1,200 ppm all the time (into late flowering stage), one of the cultivars he grows (I think it was a Kush, but I could be wrong) was not ready to harvest even at day 72. That said, I would wait for DS to chime in and correct me if I misrepresented what he told me.

According to my understanding of the science, I see no reason to reduce CO2 completely, or taper it down. However, that doesn't mean I'm correct. E.g., the rate of photosynthesis is reduced in late flowering, so the effect of CO2 could also be reduced, and maybe that means we could benefit from reducing CO2 at that time.

I think and important qualification to make is what we mean by "time to harvest". For me, I qualify when to harvest by trichome 'color'. That is, when most of the trichomes are cloudy (translucent), not clear and not amber, I harvest. At least one study found THC (and CBD) was highest when trichomes were translucent, quantified by mg of THC per trichome head.

I think the best route to take is trail and error. If you find that your strain(s) of cultivars you grow seem to take longer to harvest, without noticeable benefit, then reduce CO2. That is, until I have a chance to track rate of photosynthesis, openness of stomata, stomatal conductance, time to trichome maturity (i.e., translucent), etc., for cannabis under supplemental CO2 at harvest.

Player2 · Oct 11, 2011

Are you all sitting down and medicated? Good.

I give to you the $200 homebrew co2 setpoint controller...
http://www.co2meter.com/products/k-30-co2-sensor-module (same one as in the hydroinnovations)
http://www.auberins.com/index.php?main_page=product_info&cPath=1&products_id=1
add power supply, wire it up, put it in tupperware with holes and bammo!

It really is that easy. Auber has a few different controllers and output options depending on how you want the output switched or what you are wiring into and control/display required.

That K30 sensor is super trick. Read the info on it. It can output to lots of different things.

I am planning on wiring the controller above or this one, http://www.auberins.com/index.php?main_page=product_info&cPath=1&products_id=14 , into my hydroinnovations co2 monitor, but with a switch so I can run fuzzy logic with my bottles but switch back to how it is now for use with burners. Let us see if HI starts making it.

Even paying for the HI one and wiring in the controller with a switch, you are <$350.

spurr · Oct 11, 2011

Hey Player2,

Another great post, thanks! Feel free to post a 'how-to' when you make your mods, in this thread if you wish

. Fuzzy logic and setpoint CO2 controller for < ~$200-300?! You're my hero

@ all,

Using fuzzy logic is not for CO2 burner, only CO2 tanks, IIRC.

spurr · Oct 11, 2011

double post.

DonkDBZ · Oct 11, 2011

hashcat88 said:
I am wondering the same thing about the CAP PPM4. another preset unit which is set at 1450.

I took mine apart but am no electrician so was immediately confused. However hopefully someone can chime in...or maybe Ill just email CAP and hopefully theyll be cool and share the info.

I opened mine too. No way to change anything without a soldering gun and schematic.

Even then theres no where to attach heatsinks while removing old solder so most likely you would cook a few componants in the process.

hashcat88 · Oct 11, 2011

aww poo

@spurr yes it is set to turn on at anything >1450. the manual says it can be used with either burners or tanks.

however, it indicates level between 900 and 1450. and also less than 900.
im thinking im just going to use it as a monitor and tune my reg manually to keep the room in the 900-1450 range. good enough for me

the_extremist · Oct 12, 2011

I switched to a setpoint of 950ppm this round instead of the usual 1500 after reading this thread. I'm just finishing up week 7 of 9.5 with the Flav and they look just as fat and happy as before. If nothing else, I'm sure I'll be saving money on tank refills.

YMMV, but so far I give 1000ppm or so a thumbs up.

the_extremist · Oct 12, 2011

Also forgot to mention, it looks like the girls will ripen a bit quicker than usual as well, maybe 5-7 days I'm guessing.

spurr · Oct 12, 2011

the_extremist said:
I switched to a setpoint of 950ppm this round instead of the usual 1500 after reading this thread. I'm just finishing up week 7 of 9.5 with the Flav and they look just as fat and happy as before. If nothing else, I'm sure I'll be saving money on tank refills.

YMMV, but so far I give 1000ppm or so a thumbs up.

Also forgot to mention, it looks like the girls will ripen a bit quicker than usual as well, maybe 5-7 days I'm guessing.

Great, thanks for the info. What type of cultivar (re genetics and parents) is the "Flav"?

The facts about CO2 ppm: don't use 1,500!

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