Cab Grow fan cycle problems

ya panda man. i know. just need to know what co2 level to set on the flow meter, and how often i need to spray inside during that 50 min. exhaust fan off window.and
I don't mean "window" literally. WOULD LIKE TO KNOW how much co2 i'm loosing with my intake fan pressurizing the cab, thus releasing air through the cracks of my door zipper. BUT i don't think anybody has the answer to the ultimate question... If you have an answer to the question, yes please i'd appreciate it guys. But I've already tried all of these ideas you've mentioned already. Ecspecially the exhaust fan thing. I know all I would have to do is mount a squirrel cage fan near the top of my cab, but this is a co2 operation, I know for sure my system works better with co2. just need to get diagnostics down 2 make it run as efficient as possable

My last (the same, actually) suggestion is to not use the controller, put a 250W HPS bulb in there, run the light fan and intake fan full-time while the light is on, and setup your exhaust fan to run for ten minutes every 3-4 hours. Immediately after the exhaust fan shuts off have timers fill the chamber with co2 to 1500ppm. I guessed your growspace at 24 cubic feet so about 3.5 minutes at .5 cfh. With a *mostly* sealed box your losses of co2 are too small to care about in a time frame of 3 hours, and you hopefully wont have your plants 2" from the glass because thats a disaster no matter what because they will cook. This isn't blind advice.. this is EXACTLY what I do in my sealed cabinet except I use 400W MH/HPS because my chamber is 2x4x8 (substantially bigger). I try and keep temps at 85-87 at plant tops.

"if cold air is running in between the bulb and the glass of the reflector, then the heat will be eliminated for the most part. If you stood in a glass box with an air conditioner unit blowing air in, and a exhaust port, would you feel heat....I don't think so..You will get a tan from the radiation, but you would not feel the heat."

well we agree that in this case heat will be greatly reduced by cooling the bulb, and in a cabinet thermal energy through the glass and reflector is the biggest part. A tan is just your skin's reaction to UVA and UVB radiation and has nothing to do with what I was talking about.. Do we agree that the sun heats up the earth? Thermal energy works by transferring kinetic energy between particles, like playing pool. But when the balls get real far apart like a vacuum (space) it doesn't transfer energy, you just have hot balls with no place to dissipate energy. The only energy in a vacuum is radiation (unless you want to talk about dark energy and the string theory) and when it hits matter it will interact with it, thus the sun's radiation is the only outside source of energy the earth (hot ball) has. It just so happens the earth's atmosphere lets in mostly radiation with the wavelength of visible light, which is which is why our eyes evolved to see the colors we do and not gamma radiation, x-ray, or infrared.

A picture's worth a thousand words.....

I like your hot spot theory mrfake. I like how you explained that. Your grow box is not that much bigger than mine. same depth-yours is 6" wider- and 2 feet taller but i don't need a lot of height for a sog grow. And when I grow a single aeroponic plant for my next grow my pot will be 10" off the ground instead of 19". Then my cab would be 42 feet cubed instead of 24.4 cubic feet. When you count the light and all the other hardware the space gets smaller. How tall are your plants right now? The 400w stays. I won't spend money to downgrade. The 400 works. I know it works in here. Its just every time i get a new addition to the box, I must improvise a bit.

So let me go back to what this thread is about. Does anybody have an answer to the ultimate question? So you think I should go ahead and leave my flowmeter on .5cfm? How many cubic feet of co2 do 8 small plants normally consume in lets say 15 minutes?

i have your solution my son, but its gonna cost you:


CO2 Tester Kit



Click on image to enlarge

• Gauge proper CO2 level.

• Eliminate waste and optimize growth.

• Instructions included Inexpensive and easy-to-use!

Order


Price: Quantity:


this is from HTG supply

or this one if youve got the extra chedder laying around which seems like u do:


PPM3 - CO2 PPM Monitor/Control by CAP

click to enlargeRetail Price: $489.95
Your Price: $399.95 per EachQty: Item Code:AACCPPM3Weight: 4.00LBManufacturer : Custom Automated Products (CAP)Stock:1 Stock Breakup Model: PPM3Category: Atmospheric/Environmental Controllers

Item Description

The PPM-3 from C.A.P. is the most affordable and simple CO2 controller available. Its' proven technology is very accurate at measuring levels of Carbon Dioxide in your growing area from 0 to 5000 ppm (Parts-Per-Million). Using the PPM-3 is quite simple. Just plug your CO2 device (CO2 valve or generator) into the "piggyback" cord and it will automatically maintain the CO2 level that you specify. The PPM-3 works with any make of CO2 valve or CO2 generator (120v).

i've thought about those. have you used one before? how accurate are they? is it just a quick gage or will it give you a reading through an extended period of time , which is what i need

i had one of those ppm3 monitor/controllers $350 on ebay but i sold it when i was in the process of moving. there has got to be another way. i was thinking i'd just run it at .5cfm for 15 min then 15 min off, and also the power to my co2 timer will be tripped during the 10 min. exhaust fan cycles. do you think that will work?

hey man...sorry I haven't had much to say....guess cuz....i haven't had much different to offer that you either discount, discard or criticize. In my view....unless you are measuring your background and then monitoring the ongoing and dynamics of the current circumstances...there is no certain way to assess and evaluate the process you choose to achieve a better growing environment. I believe a meter would provide you with that assurance. But you want to find another way or in your words...theres got to be another way....ok .....fair nuf.....nuf said.

lets do the math. the co2 calculator says that it will take just over 4 mins. to fill my cab(24 cubic feet) up to 1500 ppm . So how much extra co2 am i releasing into the room for the additional 11 mins. the co2 is on. Is it enouph to compinsate for the loss of co2 during my fan OFF cycle, due to the intake fan on, leakage through the door zipper, and plant consumption? Do you know tahoe?

after googling around a commercial greenhouse uses the rule of thumb (for mature crops) .00041 lb CO2 / ft² / hr you're not commercial and mature so I'd use 25% of their numbers.... After doing the math, my opinion hasnt changed at all, except I'd run the CO2 longer (5 mins instead of 3.7) and let it "soak" in longer i.e. 4 hours between exhausting. BTW my ladies are 46" tall one week in flowering.

Merry Christmas, my internship pays me about +$20 an hour to crunch worthless info like this for them. I'd send you a bill for 18.84 but the government would take half and give it to people who don't want to work for what they got.

I do believe that although your internship pays you...$20/hr....this is the commercial and real world....I do believe that your fees should reflect the value of the advice provided....so let's say $150/hr....now open a company and do the services from within the company...and you pay....hmm...ok...15% tax....now you have a little more in your jeans to play with!

tahoe58 said:

hey man...sorry I haven't had much to say....guess cuz....i haven't had much different to offer that you either discount, discard or criticize. In my view....unless you are measuring your background and then monitoring the ongoing and dynamics of the current circumstances...there is no certain way to assess and evaluate the process you choose to achieve a better growing environment. I believe a meter would provide you with that assurance. But you want to find another way or in your words...theres got to be another way....ok .....fair nuf.....nuf said.

Click to expand...

No. Its not nuf said. Thanks for your $0.02 on the issue. I agree somewhat with everything your post said right up to the point where it says " In my view" , Everything after that makes little to no sense. All you had to do is say you don't know. instead of putting all those big words in that don't even go together. The better way involves using my brain to cordinate my flowmeter with my timer, with my climate controller, with my intake fan and not spit out the $350 for a control monitor. THAT I DON"T NEED

I guess it must be a case of ESL....cheers and good luck!

mrfake said:

after googling around a commercial greenhouse uses the rule of thumb (for mature crops) .00041 lb CO2 / ft² / hr you're not commercial and mature so I'd use 25% of their numbers.... After doing the math, my opinion hasnt changed at all, except I'd run the CO2 longer (5 mins instead of 3.7) and let it "soak" in longer i.e. 4 hours between exhausting. BTW my ladies are 46" tall one week in flowering.

Merry Christmas, my internship pays me about +$20 an hour to crunch worthless info like this for them. I'd send you a bill for 18.84 but the government would take half and give it to people who don't want to work for what they got.

Click to expand...

Lol wow thats really good stuff. Your #s look good to me, thanks a lot for the help mrfake. good shit. Well its settled then. I will start my flower cycle with co2 flowmeter at .2 cfm set with a $4 timer (15min on/15min off). Just for now, until tahoe makes a Cap ppm3 controller magically appear in my grow box.

I'm trying and I'm trying.....but my magic ain't workin'......sorry man! maybe its cause I trying to make a Ferrari 430 Scuderia appear in my garage......asking for too much I guess. cheers man, and good luck!

daddychris there is already two seperate exhaust fans. One for the 400w light which stays on when the lights are on always, and the other exhaust fan stays off for 50 mins/on 10 mins and has nothing to do with the light AT ALL. do you get it now? I keep the light fan on all day and it does not affect the co2 AT ALL. thats not the issue here. 200 cfm @ 40F going through that light is enouph, we've already established that

daddychris there is already two seperate exhaust fans. One for the 400w light which stays on when the lights are on always, and the other exhaust fan stays off for 50 mins/on 10 mins and has nothing to do with the light AT ALL. do you get it now? I keep the light fan on all day and it does not affect the co2 AT ALL. thats not the issue here. 200 cfm @ 40F going through that light is enouph, we've already established that

Damb, why did you not say that from the beginning...LOL..ok..So the problem here can only be solved three ways...Less watts....250w hps, pump cool air into your box, or try and cool off that reflector with more CFM's...Or you could spend a butt load of money on a water cooled reflector....I know you want to know how much C02 to deliver to your plants, but I have given my opinion on that. I am not worried about that, I would like to see you get your temps down in there....