[Granger2]

With nothing in room will the CO2 generator run? You can't run it for 1 24 hour period? OK. -granger

[Mikell]

Originally Posted by newestguy

Those are good finds, it is an interesting problem. I think the really pertinent part in the case of this generator is that no matter how it was set up it, if it was possible to reach the desired co2 concentration the other gas would build up enough to cause the symptoms.

It seems like in most of the other threads about it people were able to fix it by periodically venting the room. That definitely did not work here. I think it would be a fair assessment to say that different generators (or maybe different room configurations) cause different amounts of the gas.

The pic that testymctester posted is a spot on perfect example of this problem, Im glad he took it. I never pulled a plant out and really documented it. I think this happens more than people think, just on varying levels.

Well at least it makes for good reading, thought I was on to something XD

[the gnome]

testy's pic looks like the VPD I was hit with on my 1st round in a sealed enviroment.
drooping leaves, sign of a mag and or lockout issues.
never a prob unsealed and i had the same temps and RH.
but in the sealed situation these probs hit in when RH went below 60%Rh and very quickly/severely when i hit below 50%rh


btw newguy,
I went closed loop on the HW tankless Co2 gen for a while but the 40gal trash can used took up too much waste and was a prob with getting water nasties in it too fast and having to clean it more than i had time for.
i went drain to waste after, since it cycles on for less than 30sec. I doubt i dump more than 7-10gal a day

[newestguy]

The only thing I can imagine is different in my garden vs other peoples is air movement. i use a lot of oscillators. I have them all set up were they don't hit plants (or generator) directly but because there is so much bouncing off the walls everything gets at least a breeze past it. I was careful in checking that fans weren't hitting the generator, but wanted to throw it out there as the only possible difference i could imagine.

Originally Posted by Mikell

Well at least it makes for good reading, thought I was on to something XD

No you are on to something, that is exactly the issue we are talking about here. The only difference between their situation and mine is that mine could not be fixed with periodic or even constant (mild) air exchange.

Originally Posted by the gnome

testy's pic looks like the VPD I was hit with on my 1st round in a sealed enviroment.
drooping leaves, sign of a mag and or lockout issues.
never a prob unsealed and i had the same temps and RH.
but in the sealed situation these probs hit in when RH went below 60%Rh and very quickly/severely when i hit below 50%rh


btw newguy,
I went closed loop on the HW tankless Co2 gen for a while but the 40gal trash can used took up too much waste and was a prob with getting water nasties in it too fast and having to clean it more than i had time for.
i went drain to waste after, since it cycles on for less than 30sec. I doubt i dump more than 7-10gal a day

Ya I would have thought VPD myself at first, that and N tox, mag def, but I promise you what you are looking at in that picture is the effects of what ever byproduct of combustion this is.

I promise you I waited for EVER to blame the gen. it is not a good practice to start blaming things that are designed for the job they are performing. I usually start looking at any thing I have influence over. That is why I spent the 10 days after I realized air cooling fixed it. After they popped back from air cooling I turned back on the gen for 10 days and tried every conceivable arraingment of venting air, raising and lowering temp and RH. I have humidifiers and dehus in this room so I went all over the place RH wise looking for the problem. Same with temps.

Didn't think I was gonna post this thread so I didn't document it, wish I would have. I realized its a somewhat common problem when I saw it in a friends garden. Convinced him to switch to bottles and the change is undeniable. He had 2 years under his belt with his cap generator. He didn't seem to build up the problem as fast but it was there without a doubt.

[the gnome]

Originally Posted by Mikell

Alllllright. So maybe found something.

For one thing, you can try raising your temps closer to the low 80s, (tying in to the whole reason we can raise CO2, when the earths atmosphere was different and temperatures were warmer). There are calculations for specific ppm of CO2 to temp ratio, I think Snype posted them here, though I may be wrong.

Anyway,



Specifically, this post


The initial problem sounds similar, CO2 burner in a fully sealed room, plants droop and falter.

Summarized, the CO2 burner depletes O2 levels, causing incomplete combustion of the propane, leading to ethylene and SO2 build up.




At the least I've significantly added to the general confusion XD Maybe helped, maybe not, but some good reading if you enjoy that sort of mental racking.

excellent posts, lots of food for thought
things seems to come back to the O2 depletion scenario
as long as fresh air is periodically pushed in things are good.
and what exactly are the ppms when the burner is used.


maybe there's an occasional bad batch of propane,
enuff to cause these probs in grows.
if I exp. it i would go to a tank asap and not want to exp. those probs again, maybe a diff. tank of gas would make a diff.

[gmanwho]

Some generators are designed for Natural gas, some for Liquid Propane. They need to be setup correctly. I forget which one, but there is a reducing fitting that goes in the gas piping. if you have a nat gas generator an running LP there will be issues.

Just a thought..

b-safe

[Mikell]

That's a good point as well.

All you bottled users, have you got any numbers on price difference or is it marginal one way or the other? Of course it would depend on your base price per bottle, size of bottle, etc. Perhaps a good link to avoid threadjacking?

Haven't looked at bottled in awhile, but I was about to start poking around here and elsewhere for price comparisons and it might save some redundant searching.

[the gnome]

Originally Posted by gmanwho

Some generators are designed for Natural gas, some for Liquid Propane. They need to be setup correctly. I forget which one, but there is a reducing fitting that goes in the gas piping. if you have a nat gas generator an running LP there will be issues.

Just a thought..

b-safe

the only diff between nat and propane burners are the opening size on the jets, nat runs way lower pressure and has a larger opening on the jet.m
any co2 gens come with the extra jets for either one.
it probaly wont work using nat gas -->propane burner
big fire hazard immediately using propane--->gas burner

[newestguy]

Originally Posted by the gnome

excellent posts, lots of food for thought
things seems to come back to the O2 depletion scenario
as long as fresh air is periodically pushed in things are good.
and what exactly are the ppms when the burner is used.


maybe there's an occasional bad batch of propane,
enuff to cause these probs in grows.
if I exp. it i would go to a tank asap and not want to exp. those probs again, maybe a diff. tank of gas would make a diff.

I wondered about the quality of the propane as well, I sourced it many different places over this experience though. LOL, yep your right, the idea of doing any more "testing" on my stuff is not very palatable.

Originally Posted by gmanwho

Some generators are designed for Natural gas, some for Liquid Propane. They need to be setup correctly. I forget which one, but there is a reducing fitting that goes in the gas piping. if you have a nat gas generator an running LP there will be issues.

Just a thought..

b-safe

This was definitely labeled as LP and used with LP. I wondered if maybe it shipped with the wrong nozzles, maybe high altitude or something. I do not believe so though because everyone agrees the flame looks fine. If the nozzles where incorrect or if it were in fact a mislabled NG model it would have a horrible flame. It is my understanding that it is not possible to misuse the NG or LP as they just won't hook up.

Originally Posted by Mikell

That's a good point as well.

All you bottled users, have you got any numbers on price difference or is it marginal one way or the other? Of course it would depend on your base price per bottle, size of bottle, etc. Perhaps a good link to avoid threadjacking?

Haven't looked at bottled in awhile, but I was about to start poking around here and elsewhere for price comparisons and it might save some redundant searching.

Bottles definitely cost more but the return is sweet . Don't have an exact number but it gets expensive.

Originally Posted by the gnome

the only diff between nat and propane burners are the opening size on the jets, nat runs way lower pressure and has a larger opening on the jet.m
any co2 gens come with the extra jets for either one.
it probaly wont work using nat gas -->propane burner
big fire hazard immediately using propane--->gas burner

This is the impression I got from everyone when I asked if it was possibly mislabeled. They said it wouldn't hook up.

[gmanwho]

the generator hook up side probably would be the same. the connecting supply hose end would be different. My cap gen is fully interchangeable. But you say the flame is good. I'm not sure what a lp flame would look like on an nat gas burner.

ya man, the return is sweet when everything works correctly. I can say i seen a difference from running 1000ppm or 1500. Atleast for my setup.

i felt things stalled at 1500. I noticed this directly as the Res water levels werent dropping as much. Meaning the plants where uptaking less. I started 800, then 1000, then 1200 then 1500 over a few days. as i raised the ppm past 1200 i started adding less back to the res. Meaning the plants uptake had slowed during the 1500 vs 1000. i then lowered back to 1000 an by the end of that light cycle i noticed they started uptaking more nutes again. then i said " a 1000 ppm would be cheaper to run from aspects anyways.." less heat, less fuel.

as growshopfrank said, i'd be curious to see the flame after not opening the room for awhile. i have read somewhere that there is a poisonous gas byproduct produced in a flame when the oxygen levels are reduced. ethyl gas type by product, i think.

hope you figure it out .. b-safe