CO2 Enrichment

[DoubleAtotheRON]

Got the system in for this summer’s experimental run with some new medium, and cutting out Mammoth altogether. Just Tiger Bloom and 50ml of CalMag per 50 gallons at 1000 ppm on the mix. Don’t know if it’s my imagination or what, but I think we have better looking plants at day 17 of flower this run. I discovered that we can prob run the full room in the summer heat with a sealed room, and are running 2 of 3 rows of lights, and I still had to turn the AC up, as it was too cold in there. So, I’m kinda pumped about that. Anybody know if you would ever have to vent if everything is under control?

 

[Keesje]

I don't get the question...
Vent for what?

 

[Renfro]

Anybody know if you would ever have to vent if everything is under control?

Other than an AC failure and using the blower for backup cooling (always run at night just in case), the only other reason would be a potential ethylene gas buildup (just purge the room at lights out). But if you have an AirROS unit then you won't have to worry about ethylene. Ethylene gas can promote early ripening and thus lower yields if at higher concentrations.

 

[Renfro]

On a side note, I bet you are glad you didn't wait too much longer to flip those, they filled out your tables pretty well.

 

[Keesje]

In principle, the largest source of ethylene in a growroom are your plants, but the plants alone never produce so much ethylene that it is harmful.
A harmful amount is most of the time only created when other sources also produce ethylene.
The most common sources are malfunctioning heaters or CO2 burners and rotting plant material.
Also don't smoke in your room.
Plants and fruits that are harvested and transported and stored have a higher chance of too much ethylene.

 

[DoubleAtotheRON]

I don't get the question...
Vent for what?

I suppose I meant vent to turn over any stale air. Air circulation is very good in this room, but was just wondering if you need to purge the sealed room every now and then. I’ve never used a heater. .. no need for it.. the CO2 system is new and working very well.

 

[DoubleAtotheRON]

On a side note, I bet you are glad you didn't wait too much longer to flip those, they filled out your tables pretty well.

Oh hell yeah.. good call brother!

 

[Renfro]

The ventilation system is definitely a crop saving device in the event of an AC failure.

In my rooms I put my side lighting on a high temperature shutoff and I have my autopilot setup with a day temp set a few degrees above where the AC holds my room and the temp : CO2 locked. So if the AC fails and the temps start to rise, three things happen:

1) The autopilot sees the temperature rise and turns on the intake blower
2) Because the Autopilot is set to locked temp and co2 it will stop running the co2 generator during vent cycle
3) The high temperature shutoff will kill my side lighting to reduce the heat load

So if you're not around and the AC quits on you for some reason those automated reactions will save a crop from cooking.

 

[Keesje]

I had a discussion about this in another thread.
'Stale air' and 'fresh air' are ways us humans experience air quality.
We feel uncomfortable in a room with a high humidity and high levels of CO2.
Then we open a window to let fresh air in and level out the CO2 level.
So for example from 1200 ppm back to 450 ppm.

Plants don't have that problem.
There is always plenty of O2 in a room (air contains about 20% of O2 and before the roots could absorb all the O2 in your room - even if it would be 100% sealed (which it never is) - it would take weeks and weeks.
CO2 levels can hardly get too high, and I also think you control that very well.
So not need to vent for those reasons.

 

[DoubleAtotheRON]

I had a discussion about this in another thread.
'Stale air' and 'fresh air' are ways us humans experience air quality.
We feel uncomfortable in a room with a high humidity and high levels of CO2.
Then we open a window to let fresh air in and level out the CO2 level.
So for example from 1200 ppm back to 450 ppm.

Plants don't have that problem.
There is always plenty of O2 in a room (air contains about 20% of O2 and before the roots could absorb all the O2 in your room - even if it would be 100% sealed (which it never is) - it would take weeks and weeks.
CO2 levels can hardly get too high, and I also think you control that very well.
So not need to vent for those reasons.

Thanks man!

 

[DoubleAtotheRON]

The ventilation system is definitely a crop saving device in the event of an AC failure.

In my rooms I put my side lighting on a high temperature shutoff and I have my autopilot setup with a day temp set a few degrees above where the AC holds my room and the temp : CO2 locked. So if the AC fails and the temps start to rise, three things happen:

1) The autopilot sees the temperature rise and turns on the intake blower
2) Because the Autopilot is set to locked temp and co2 it will stop running the co2 generator during vent cycle
3) The high temperature shutoff will kill my side lighting to reduce the heat load

So if you're not around and the AC quits on you for some reason those automated reactions will save a crop from cooking.

Awesome. Good thing is, I’m 17 steps away from the grow, and I go out there a dozen times a day, so I’d catch a problem pretty quick. If the ac shits the bed at night, no biggie. My brother is a HVAC guy, and I can call him on the spot and he’ll come fix me up in a jiffy.

 

[Keesje]

Your plants look really nice, I have to say.
I personally would design the room different, but if it works for you, it works.

 

[DoubleAtotheRON]

Your plants look really nice, I have to say.
I personally would design the room different, but if it works for you, it works.

Meh.. it was my first room.. I would do some things differently as well now that I have grown in it for a couple of years. What did you have in mind?

 

[Keesje]

I would get rid of the boards and use fixtures with bars.
Led strips really offer much better light distribution than boards do. The thing is, you need to hang boards higher to get better uniformity. And thus therefore the more light you will waste on the walls.
I would create 'walls' around your plants. You are wasting a lot of light. The light shines on nothing. It just disappears in the room, lighting your equipment for example. One should always try to get as much lights on ones plants. With walls it can reflect back to your plants.

 

[DoubleAtotheRON]

I would get rid of the boards and use fixtures with bars.
Led strips really offer much better light distribution than boards do. The thing is, you need to hang boards higher to get better uniformity. And thus therefore the more light you will waste on the walls.
I would create 'walls' around your plants. You are wasting a lot of light. The light shines on nothing. It just disappears in the room, lighting your equipment for example. One should always try to get as much lights on ones plants. With walls it can reflect back to your plants.

Well, I spent about $15,000 on these HLG’s, so I’ve got a bit before they come to the end of their life cycle and need to be replaced. I do have about a 4x100 foot sheet of Mylar I’m debating on putting up on the walls. These 3 trays move 17 inches either way, and I shift them every day.. kinda like light movers. But I get what you’re saying. Edit: I’m only growing 1 tray this summer as an experiment.. we normally have all 3 trays and 18 HLG’s running. You can see the last grow in my signature.

 

[XtraGood]

What are you using as a controller for the co2?

 

[DoubleAtotheRON]

What are you using as a controller for the co2?

A Spartan total environment control unit seen in the first post.

 

[Keesje]

Well, I spent about $15,000 on these HLG’s, so I’ve got a bit before they come to the end of their life cycle and need to be replaced. I do have about a 4x100 foot sheet of Mylar I’m debating on putting up on the walls. These 3 trays move 17 inches either way, and I shift them every day.. kinda like light movers. But I get what you’re saying. Edit: I’m only growing 1 tray this summer as an experiment.. we normally have all 3 trays and 18 HLG’s running. You can see the last grow in my signature.

Then I would wait as well! Wow, that is a lot of money spend.
You can put the mylar on the wall, but you could hang is also as a curtain to the open sides.

 

[DoubleAtotheRON]

Then I would wait as well! Wow, that is a lot of money spend.
You can put the mylar on the wall, but you could hang is also as a curtain to the open sides.

As my buddy @Renfro says .. “you gotta spend money to make money.” Id really like to have the new R spec 650’s. .. but, as led technology gets better and better, we will upgrade in the future.

 

[XtraGood]

@DoubleAtotheRON You mentioned that after growing there for a few years you would change some things if you did it again from scratch. I was thinking about building a smallish metal shop type building in the not too distant future and am getting a features list together, not much on the list yet: concrete pad, floor drains, insulation (what type?), sealed, mini-split, 220v, __________. Any advice you have I'd happily take.