i have started to use co2 with my nft system. i have the cf at 1.8. and some leaves look like they are missing some nutrients. before useing co2 the plants previous looked fine. i do get a much bigger harvest though. i have also tested the co2 in the air and it is around 1500ppm all the time apart from extraction. i read something that said if you use co2 you should increase the ammount of nutrients. is this right and what should i increase to.

When using the CO2 the plants are able to uptake the nutes in a more rapid way, basically, it is like steraroyds, when you take them, you would need to eat more protein and carbs to keep up with the new demand for muscle building blocks. Same with the plants, the CO2 acs as a catalyst which allows the plant to grow at an accelerated rate, but needs more food to keep up with the demand.
As far as the type of increase, you should just bump it up and listen to them IMO.
Adieu

__________________
"If what shone afar so grand,
Turn to nothing in thy hand,
On again; the virtue lies
In struggle, not the prize."--R. M. Milnes.
Hugh Miller said the only school in which he was properly taught
was "that world-wide school in which toil and hardship are the
severe but noble teachers."

i myself have never had the luxury of co2 ,
from my reading i was under the impression your nutes ppm. should be = to your co2 ppm. are they at all close ?
crispi

Are co2 system expensive?

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Yes Xcrispi that is a rule of thumb that many do use, but I haven't found a real documented grow that compares using nutes on a typical schedule compared to using the nutes at the same level as the CO2 PPM.
Razz CO2 controllers run between 5 and 900 bucks for a decent set up. Mind you, this doesn't include the CO2 tank or propane if you go with a CO2 burner rather than a CO2 tank. With a good CO2 control package you will be able to make sure your CO2 is staying at the programmed levels because there will be a probe that monitors the levels in the room making sure that they are not to high or to low. You will usually have a photo sensory monitor that makes sure that once lights go out that the CO2 is no longer released. You will probably have a timer that can allow you to program desired CO2 treatment times, and all of the connections, solenoid, tubes and so on as well.
Adieu

__________________
"If what shone afar so grand,
Turn to nothing in thy hand,
On again; the virtue lies
In struggle, not the prize."--R. M. Milnes.
Hugh Miller said the only school in which he was properly taught
was "that world-wide school in which toil and hardship are the
severe but noble teachers."

The guy at the hydro store told me I could get started for under $300, that's without controllers. How does this cheaper type of system work? He said I would just set up the co2 to release at certain points, and then put the fan on a timer to make sure it's not on while co2 is. Anyone have experience with the cheaper alternative?

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Let the good times roll!!

I thought that
Zandor had a growfaq about Co2...which would probably explain about the strength and balance needed. peace

I think the FAQ just says to keep the CO2 PPM at 1500 when ever in use and does not really address the nute question.
Adieu

__________________
"If what shone afar so grand,
Turn to nothing in thy hand,
On again; the virtue lies
In struggle, not the prize."--R. M. Milnes.
Hugh Miller said the only school in which he was properly taught
was "that world-wide school in which toil and hardship are the
severe but noble teachers."