Does CO2 rich environment have an impact on a hydroponic reservoir?

[gwhunran]

Good morning fellow growers,

I usually supplement with CO2 in my grows using self made fermentation buckets. I am in the process of installing a CO2 system in my grow area, that will be operational for the start of my Spring 2024 grows.

My questions revolve around the CO2s effect on the PH of my reservoir.
The gas is heavier than air and sinks toward the floor, and even though I'm keeping it stirred up with fans, the concentration is still highest at floor level. My air intake on my air pumps aerating the reservoir is near the floor. So, the air pump is supplying CO2 rich gas into my reservoir, along with the ambient air. CO2 is an acid, Carbonic acid to be precise. In the amounts used, does this have an effect on the plants? Good or bad?

I worked for a CO2 company in my youth, and one use, was to inject it into industrial wastewater to lower the PH before discharge. This is the reason for my query.

 

[Absorber]

Are you able to have the reservoir outside of the tent?

 

[gwhunran]

Are you able to have the reservoir outside of the tent?

No, my reservoirs are directly under the inflow/outflow fittings, under the tray. I thought about mounting the air pump higher on the wall and putting a hose on the air pumps air intake and running it vertically towards the ceiling, to get it above the highest concentration.

My grow areas are in a room divided with a false wall

1. I don't know if adding a hose to the intake will cut down too much on the volume of air it takes in.

2. I don't know if the added CO2 in the parts per million we're talking about is even significant.

 

[bluter]

doubt you'll have any issues with it. c02 needs a lot of other environmental support to be close to useful. it's highly unlikely the set up you describe would cause any problem.

 

[gwhunran]

Finally set everything up on the CO2 system. Still have to do some hose and cable management.

CO2 system set up. Note the Y valves. Either, both, or none, to the rooms.

CO2 output terminations above the high mounted fan.

Closer picture of the output end of the CO2 hose on one side. Didn't take a picture of the other side but it's done the same way.

CO2 hose running down from the fan to the floor and to the left and back to the Y fitting.
d

Picture of the air pump mounted to the wall. I mounted it to the board over a piece of Dynamat sound deadner to kill some of the vibrations.

Another picture of the air pump mounted to the board as high a possible. The air intake hose is about 3'/91cm long. The hose terminates near the maximum of most of my grows highest point. Do you think the intake hose will over stress the air pump, @West Hippie

 

[SmokingWings]

My questions revolve around the CO2s effect on the PH of my reservoir.

The CO2 is acidic and when it combines with the water it will start to form carbonic acid. I am thinking that the best way to figure out if the new CO2 system will have an effect on the pH of the reservoir(s) would be to take pH readings a couple of times for several days. Then once the CO2 system is started up and running take a couple of readings a day for several more days.

Write down the numbers and after several days if the new CO2 is going to have any sort of effect you should be able to see it in the numbers. More than once I have seen reports from indoor growers and aquarium folk that their pH adjusted water did start to show a drop within a day when it had been left out in buckets and exposed to the air.

Since you have already used fermentation buckets I am thinking that the new system might not have much of an effect on the water's pH unless both the buckets and the tanks are running full bore at the same time. But the only way to tell for sure is to do the pH testing before and after.

 

[gwhunran]

The CO2 is acidic and when it combines with the water it will start to form carbonic acid. I am thinking that the best way to figure out if the new CO2 system will have an effect on the pH of the reservoir(s) would be to take pH readings a couple of times for several days. Then once the CO2 system is started up and running take a couple of readings a day for several more days.

Write down the numbers and after several days if the new CO2 is going to have any sort of effect you should be able to see it in the numbers. More than once I have seen reports from indoor growers and aquarium folk that their pH adjusted water did start to show a drop within a day when it had been left out in buckets and exposed to the air.

Since you have already used fermentation buckets I am thinking that the new system might not have much of an effect on the water's pH unless both the buckets and the tanks are running full bore at the same time. But the only way to tell for sure is to do the pH testing before and after.

I check on the grows twice a day normally. Topping up the reservoir daily and twice a day when the plants get bigger. I check PH and adjust as needed each time. I plan on running a bucket at some point and unplugging the regulator. That will allow the Controller to act as just a monitor. It should give me some idea what my buckets have been doing all these years. I have a spare controller that @West Hippie gave me, that I will mount in the other grow area, to give me CO2 readings only. When the grow areas are on the same light cycle, the closure between grow areas is open, so it's just one room. If the other controller breaks, I can just swap them out.

 

[gwhunran]

I check on the grows twice a day normally. Topping up the reservoir daily and twice a day when the plants get bigger. I check PH and adjust as needed each time. I plan on running a bucket at some point and unplugging the regulator. That will allow the Controller to act as just a monitor. It should give me some idea what my buckets have been doing all these years. I have a spare controller that @West Hippie gave me, that I will mount in the other grow area, to give me CO2 readings only. When the grow areas are on the same light cycle, the closure between grow areas is open, so it's just one room. If the other controller breaks, I can just swap them out.

The cubic area of both grows combined, one room, is about 500 cubic feet. 8x4x16

 

[SmokingWings]

I check on the grows twice a day normally.

That should help. If you have to adjust the pH more often after the new system is up and running then it is having an effect of the reservoir. I am thinking it should only take a couple of days to find out.

 

[gwhunran]

That should help. If you have to adjust the pH more often after the new system is up and running then it is having an effect of the reservoir. I am thinking it should only take a couple of days to find out.

Agreed.

 

[Delps8]

Even adding small amounts of CO2 to the air improve crop yield. We see this in the large because one of the factors contributing to increased greening of many areas of the planet is the increase in CO2 levels across all areas of the globe.

This is demonstrated "in the small", arguably daily, by students around the globe who run simple experiments as part of their science classes. That happens at all levels and is no mystery.

One researcher of note, Bruce Bugbee, states that the first change you should make in optimizing your grow environment is to increase CO2 levels. The reason for this is that it's more cost effective to add CO2 than it is to increase PPFD.

What this makes clear to us in the cannabis world is that we don't need to optimize the environment in order for CO2 to be beneficial. Just add more CO2 and you get more weed. Most growers don't have the resources to create a closed loop system but, seeing that you've taken that step, you will receive an immediate benefit as soon as you increase your CO2 levels.

To your point about the impact on your reservoir - I have no idea.

I try not to figure things out by experimenting on my own grows. There are so many confounding variables outside of a laboratory, for one, but I also avoid that approach whenever possible for the very simple reason that "the pioneers take the arrows in the chest while the settlers get the land." My rationale is that others have dealt with this issue and have the answers - I can't take the time or the risk to try to figure out what's already known.

It's not issue of the answer being unknown; it's an issue of me being able to find the answer.

In this case, I'd look to see the experience of others (google is your friend) or spend some $$ to contact someone who knows. Only as a last resort would I subject my grow to something that might be a damaging to my plants. It's not only fraught with error but it's also a time and money sink. I use seeds for my grows and they run, say, $15 per seed. Add in a few hours of my time and it's much cheaper to contact "a pointy headed guy" and ask questions instead of doing a recon-by-fire with my plants.

Two names that come to mind are Dr. Fernandez, the author of HydroBuddy, and Harley Smith, who has a series of YT videos, who can be reached at harley.pht@gmail.com.

I've read Fernandez' site over the past few years and he's quite credible; he knows his chemistry and he knows how to write software (I've been writing software for a living for > 30 years so I have some expertise to judge his software). Harley Smith? Well I'd recognize him if he walked up to me! but other than that, the best I can come up with is that he appears to be credible. Either way, the cost of an hour of their decades of expertise is minimal and you'll probably either get an answer (I'd bet Fernandez will have that info on the tip of his tongue since it's essentially a chemistry question) or, if that's not the case, they'll be able to get back you with very quickly. All in all, it's a cheap, low risk way to get knowledge very quickly. That's why people hire consultants.

Oh, and Merry Christmas.

 

[gwhunran]

Even adding small amounts of CO2 to the air improve crop yield. We see this in the large because one of the factors contributing to increased greening of many areas of the planet is the increase in CO2 levels across all areas of the globe.

This is demonstrated "in the small", arguably daily, by students around the globe who run simple experiments as part of their science classes. That happens at all levels and is no mystery.

One researcher of note, Bruce Bugbee, states that the first change you should make in optimizing your grow environment is to increase CO2 levels. The reason for this is that it's more cost effective to add CO2 than it is to increase PPFD.

What this makes clear to us in the cannabis world is that we don't need to optimize the environment in order for CO2 to be beneficial. Just add more CO2 and you get more weed. Most growers don't have the resources to create a closed loop system but, seeing that you've taken that step, you will receive an immediate benefit as soon as you increase your CO2 levels.

To your point about the impact on your reservoir - I have no idea.

I try not to figure things out by experimenting on my own grows. There are so many confounding variables outside of a laboratory, for one, but I also avoid that approach whenever possible for the very simple reason that "the pioneers take the arrows in the chest while the settlers get the land." My rationale is that others have dealt with this issue and have the answers - I can't take the time or the risk to try to figure out what's already known.

It's not issue of the answer being unknown; it's an issue of me being able to find the answer.

In this case, I'd look to see the experience of others (google is your friend) or spend some $$ to contact someone who knows. Only as a last resort would I subject my grow to something that might be a damaging to my plants. It's not only fraught with error but it's also a time and money sink. I use seeds for my grows and they run, say, $15 per seed. Add in a few hours of my time and it's much cheaper to contact "a pointy headed guy" and ask questions instead of doing a recon-by-fire with my plants.

Two names that come to mind are Dr. Fernandez, the author of HydroBuddy, and Harley Smith, who has a series of YT videos, who can be reached at harley.pht@gmail.com.

I've read Fernandez' site over the past few years and he's quite credible; he knows his chemistry and he knows how to write software (I've been writing software for a living for > 30 years so I have some expertise to judge his software). Harley Smith? Well I'd recognize him if he walked up to me! but other than that, the best I can come up with is that he appears to be credible. Either way, the cost of an hour of their decades of expertise is minimal and you'll probably either get an answer (I'd bet Fernandez will have that info on the tip of his tongue since it's essentially a chemistry question) or, if that's not the case, they'll be able to get back you with very quickly. All in all, it's a cheap, low risk way to get knowledge very quickly. That's why people hire consultants.I

Oh, and Merry Christmas.

Thanks Delps8, I'll do a little more digging. I won't be starting a new grow until spring, so I've got some time. I've been running mash buckets(bier) in my grows for years and never measured the amount of CO2 filling the space. The smell of the gas being released into the room was detectable to the nose. I'll run a bucket in the room, with the regulator shut off, to get a baseline for the buckets.
I think all I need to do, is keep a close eye on the reservoir PH and make sure it doesn't get or at least not stay too low.

 

[Delps8]

Thanks Delps8, I'll do a little more digging. I won't be starting a new grow until spring, so I've got some time. I've been running mash buckets(bier) in my grows for years and never measured the amount of CO2 filling the space. The smell of the gas being released into the room was detectable to the nose. I'll run a bucket in the room, with the regulator shut off, to get a baseline for the buckets.
I think all I need to do, is keep a close eye on the reservoir PH and make sure it doesn't get or at least not stay too low.

I suspect that you're avoiding a lot of the issue by keeping the air inlet near the top of the tent.

Overall, this is a chemistry issue, to my way of thinking, perhaps it's as simples just dealing with how many mols of a gas X are absorbed by water at standard temperature and pressure. That's a worst case, though, because your res will be full of "vitamins and minerals" (just like Pop Tarts!). That's a long way from two H's and an O so the impact of the extra CO2 might get…lost in the weeds. ;-)

BTW, I bring up the pointy headed guy idea because I want together a list of questions that I can bring up before I rent one of them. I'd like to get answers from Bugbee but I'd suspect that he's in a different price range than Fernandez or Harley Smith. Both of those guys are $150 per hour which is worth it to me. I pissed away hours of my time in early 2021 when I followed really bad advice to "fix" my res to stop pH from dropping.

 

[gwhunran]

I suspect that you're avoiding a lot of the issue by keeping the air inlet near the top of the tent.

Overall, this is a chemistry issue, to my way of thinking, perhaps it's as simples just dealing with how many mols of a gas X are absorbed by water at standard temperature and pressure. That's a worst case, though, because your res will be full of "vitamins and minerals" (just like Pop Tarts!). That's a long way from two H's and an O so the impact of the extra CO2 might get…lost in the weeds. ;-)

BTW, I bring up the pointy headed guy idea because I want together a list of questions that I can bring up before I rent one of them. I'd like to get answers from Bugbee but I'd suspect that he's in a different price range than Fernandez or Harley Smith. Both of those guys are $150 per hour which is worth it to me. I pissed away hours of my time in early 2021 when I followed really bad advice to "fix" my res to stop pH from dropping.

The inlet mounted higher is new. I had the air pump on a cinder block, taking air in from that level. The white board is mounted to the false wall, so it will become a mounting surface for many items now. It gave me the opportunity to get the pump up off the floor and raise the intake above where I'll be keeping the CO2 Controller sensor.