Howdy all. JunkWerks here. Long time grower (mostly micro), first time poster, but I'd like to do my part. This forum is amazing and invaluable to the cause. Thank you all! I hope the following helps those of you who would like to add some horsepower to your grow. It has certainly helped me. A buddy of mine who has been doing clandestine grows for years in a college town that shall remain nameless let me in on one of his secrets - A dry ice sublimator for CO2 enrichment. He says that I can release the tek (with my own refinements, of course) to the forums (not like the concept was a big secret or anything) as long as I call it the "Sublime Sublimator". The shit works and I’ll call it "Rumplestiltskin" if it ups my yields….
Let me preface this by saying that the Sublime Sublimator is NOT A REPLACEMENT for commercial CO2 enrichment systems. There are, however, certain instances when a device such as this is damn useful. In some locations, bottled gas retailers are not conveniently located. Some of the more cautious (paranoid) folks don’t want to incur any security problems from obtaining bottled gas. Other people may be reluctant to add to the growing energy crisis by burning natural gas to create CO2. Still others (such as the creator of this tek and myself) live or work in places where dry ice(DI) is plentiful and cheap and/or free. He got his from the biology lab at the university. I myself didn’t even consider doing something like this until the local Vons started selling Penguin Brand Dry Ice. And even then, it was $1.00/lb which wasn’t very economical. But then we discovered that though it was priced per pound, it rang up as a barcoded $1.00 item. So as long as the “sale” on DI was going on, I was determined to capitalize on it. If you find yourself in a similar situation, I highly recommend giving DI CO2 enrichment a shot. And now, without further ado:
DIY Dry Ice CO2 Enrichment System, AKA "THE SUBLIME SUBLIMATOR"
Sublimation is the transition process from a solid to a gas. And left in the open air at average (65-75F) room temperatures, a five pound block of DI will completely sublimate in a few hours. The FAA conducted a detailed and thorough scientific study of DI sublimation rates. DI is used extensively in the air shipment of perishable goods, and they were looking into the hazards of CO2 buildup in an enclosed aircraft. The rates varied, depending on ambient temp/pressure, particle size, and insulation. Bottom line (and Chem 101 basics), the sublimation rate of DI can be extended by putting it into an insulated container. Add a small hole and connect a hose to it and bam – you’ve got a sublimator. Pretty simple eh? The Sublime Sublimator adds some technical refinements that make the system more efficient and easier to use.
--------------------------
PARTS LIST:
--------------------------
DRY ICE VESSEL –
The heart of the device, it should be insulated and AIRTIGHT. For my purposes, I hit up the Home Despot and grabbed a Bubba Keg 384 3-gallon beverage cooler/dispenser. $29. I like working with coolers like these because they’ve got holes pre-drilled. Gatoraide coolers might work, but the Bubba is choice because has an interlocking lid with a rubber seal built into the lid. If you can get your hands on a dewar or vacuum thermos bottle, that would be ideal. I picked the because it’s cheap and readily available, something the forums appreciate (I know I do).
HOSE QUICK CONNECTOR –
I used a 1/2 ‘’ nylon quick connector. $1.60. It has a built-in bushing and a rubber gasket. It’s also a compression fit which eliminates the need for brass wedges and Teflon tape. Most importantly, it will stand up to continuous removal and insertion of the hose (which we’ll get to later). Check the size of the valve. Look inside the cooler and you will see that there is a nylon hex nut that keeps the valve secured to the fitting. Unscrew this to determine what size you need. I even went as far as taking the nut to the plumbing section and dry-fitting it until I found the right size.
FEED HOSE –
10’ of 1/2” Polyethylene hose, available in the plumbing section. $5.99 It’s pretty durable, and has a thermal range good for our purposes. Avoid rubber, or polypropylene (aquarium hose) as it is not as thermally forgiving and can crack/degrade. There is an issue with C02 leaching plastics over time, but I’m told that this is not an issue. Apparently it takes a long time. I’ve cut my hose to a more manageable 5’ length anyway, so I have a spare if necessary.
INSULATION –
The Bubba Keg on its own provides some insulation, but not much. Certainly not enough to extend the life of a DI block beyond a day. My initial design for this was to put the DI in a Tupperware container until my friend turned me onto the Sublime Sublimator design. I found some R-6 foil backed duct insulation that works great. $6.00 If you have the space (I don’t in my setup) you could use exterior-grade R-30. If you do, please let us know how that works.
DISPERSAL FAN –
El cheapo-crapo $5.00 Wally-Mart special seems to work fine. I’m sucking enough power as it is, so I didn’t want to add to that tally by much. If you’ve already got an oscillating circulator fan in your setup, that will work just fine.
HANGING FISH SCALE –
I can only imagine how much money big box stores like Wal-Mart and Home Depot make off of people like us. This thing was about $5 bucks and registers all the way up to 50lbs, more than suitable for the amount of DI we’re sublimating.
TWO-PART EPOXY –
JB weld or the like. Just be sure that it cures fast and has a good thermal range in the lower end.
FOIL TAPE –
Nashua USED to make foil tape without a crummy Teflon backing to it. If you can find it, get it. Usually listed under “industrial” or “heavy duty”. If not, I suppose any tape will do. Foil is essential though, as it doesn’t react to temps as adversely as duct or electrical tape. DO NOT use masking, strapping, or packing tape. You’ll be sorry.
48” NYLON ZIP TIES –
We will use these to affix the insulation to the unit. Available in the electrical or plumbing section. Also nice to have on hand at work if someone asks you “Hey man, do you have any zip ties?” Tell them sure, and whip out the 4-footer. I guarantee they’ll never ask you for anything again.
CRAFT WIRE
GLOVES
A HAMMER
TOTAL COST: About $60
--------------------------
FABRICATION PROCEDURE:
--------------------------
STEP 1 – REMOVE KEG VALVE –
As I said before, there is a nylon hex nut that keeps the valve secured to the fitting. Remove this and the valve should simply unscrew. Toss the valve into your ever-expanding bonus part box. Keep the nut.
STEP 2 – INSTALL QUICK CONNECT –
The quick connect fitting should pop into the hole pretty easily. Now, Chinese manufacturing tolerances being what they are, you may find that the holes between the inner wall and the outer wall do not quite line up. This is fine, and one of the main reasons for the 2-part epoxy. When you have established the best dry-fit you can, break out the epoxy, mix it up, and smear the collar of the fitting liberally. Slide this into the hole and then screw on the nylon nut. Epoxy the nut to the inside as well and let the new assembly cure overnight. It is very important to get good epoxy seals, otherwise you will be losing precious CO2.
STEP 3 – SEAL THE LID VACUUM-RELEASE VALVE
Now, while your DI vessel is curing and you’ve still got some epoxy left, we can take care of that pesky vacuum release valve on the lid. Most beverage coolers will have a small hole drilled through the lid for this purpose, although on fancier systems they include a one-way gasket valve. Either way, that shit must go or your system will lose pressure. Epoxy the hole/valve and then place a strip of foil tape over it. Done and done.
STEP 4– AFFIX INSULATION
This is my favorite part of the operation because once it’s complete, the Sublime Sublimator looks less like some kludged K-mart shit and more like something NASA would build. Indeed it does resemble an onboard O2 tank. The best way to do this is to take the insulation, wrap it around the vessel, and let one edge overlap by a few inches. (Safety pro tip: Baby Powder your forearms and be sure to wear gloves and a longsleeve shirt you don’t mind tossing out afterwards. Cuz Fiberglass is fo-ev-a, yall.) Cut the insulation with large scissors or shears, and set aside the rest. Foil tape one side to the vessel and then wrap it carefully around. Have one of the big zip ties handy and affix the insulation with it. Don't cinch it tight. Remember, insulation works because it creates an inert gap between the container and the outside edge. Too much compression will reduce it's effectiveness. Use the remaining bit to create a square for the bottom. Foil tape the bottom piece to the side insulation..
STEP 5 – DRILL HOLE FOR SCALE
The scale is to help you determine how much DI you’ve got left in the tank. If you use the Bubba keg, a horizontally-drilled 7/16 hole will do fine. The load hook of the scale should slide easily through. Pressure should keep it from slipping out.
BRAVO! You have, in fact, “gotten her done”.
--------------------------
INSTALLATION AND USE:
--------------------------
ROOM SEALING –
Do your best to seal up the room. You might have already done this (I hope so) for odor control. Spray foam insulation, as well as caulk and DIY weatherstripping kits all work well for this. Big cracks are a no-no, so if you can see light with the door closed, you know where the leaks are. You will never get them all, but it makes little sense to go through all of this and not seal up the gaps. You will waste, time, money, and the CO2 destined for your plants will instead pollute the environment before it has a chance to be absorbed and converted into something more useful. Basically, what I’m saying is no half-assed hippie bullshit, if you please.
DI VESSEL PLACEMENT -
The vessel needs to hang in order to get a good reading of its capacity, so a floor beam or attic joist is good for upstairs/downstairs setups. A sturdy nail is good, a bolt is better. Just make sure that it’s secure. Closet and small rooms - hang from a high shelf or sit outside the room. Since the Sublime Sublimator is a passive system and will pretty much work no matter what, you can put the thing anywhere. But the best place is AWAY from any heat source. This especially includes ballasts and other electrical devices! The first few inches of the hose will be VERY COLD. Condensation and eventually ice will build up and drip onto anything nearby. You could insulate the feed if you like. My cement floor doesn’t mind a bit of water so I just let it drip. You also want it somewhere that you can get to conveniently for reloads, so factor that into your plan as well.
FEED HOSE -
Insert the hose into the quick connector and push. It should slide home snug. If you pull on it, it should not come loose. Run the hose from the vessel to the area behind your dispersal fan. A few inches above the fan works good. Secure it with wire or tape. Make sure that you have at least a foot or two of slack at the other end. Shorter hose lengths are more efficient, but longer lengths allow you to reload the system without removing the hose. Your choice.
LOADING THE DRY ICE -
Now comes the fun part. Once you have obtained your DI ( and I recommend 10lbs per load), set it aside. Disconnect the hose if necessary. Before you load the vessel, you’ll need to tare it out first. Hang it by the scale and note the reading. My approximate tare weight was around 5lbs. Take it down and unscrew the lid. For store-bought DI users you will need two 5lb bags. Take the first bag and drop it into the vessel. LEAVE THE ICE IN THE BAG. The plastic bag is a vapor barrier and slows down the sublimation rate. Don’t worry about the bag, it has holes in it and the CO2 will eventually escape. Now, with gloves and safety sunglasses in place, smash the second bag of dry ice to bits with the hammer, making sure not to destroy the bag in the process. Open the bag and dump the small pieces into the cracks around the large block. The idea is that the smaller pieces will help to lower the ambient temps of the vessel and slow the sublimation rate of the block. Either way, the CO2 is gonna wind up in your growing chamber, so no problemo.PLEASE BE CAREFUL WITH DRY ICE. It is colder and more dangerous than you may think. Always wear gloves when handling it or you will suffer burns!!!
LEAK-PROOFING AND HOSE TEST –
When the system is loaded to the brim, take a few ounces of warm water and pour it onto the ice. WOW, SCIENCE! Everybody has seen this effect before. You are creating dense H2O/CO2 fog that makes rockstars look hella cool and will allow you to test the integrity of your seals. Put the lid on quickly and lock it down. You should see some of the vapor escaping the seal, once again, Chinese tolerances will kill us all. Place a band of foil tape around the lid gap and that should seal the thing tight. Now if you look at the opening or the end of the hose, you will see the vapor pouring out. Cover your finger over the hole for a moment (it won’t hurt you) and check for any other leaks. Patch with foil tape as necessary. You should not have any leaks around the epoxy area. Connect the hose back and hang the vessel once again. The new weight minus the tare will give you your total C02 load (in this case, around 10lbs). MAKE NOTE OF THE TIME! This is a crude system, but we can still calculate approximate sublimation rates. Check your grow chamber and make sure that the hose is connected to the fan intake properly. That’s it.
FAN CYCLES AND SAFETY –
You should already be running an exhaust fan. Even with CO2, venting is essential for growth and temperature control. There are a variety of ways to vent things and I’m sure you have read them all so I won’t go into it here. Just be sure that you switch any continuous fan to run periodically instead. I myself invested $70 in a short cycle timer and I have it run on a 5minute on/4 hour off cycle. The CO2 will be constantly building up, unlike valved systems, so this scheme works just fine. You can play with your fan timers. The less they run, the more CO2 your plants will have. SAFETY PRO TIP – Purge your grow chamber before working inside it! CO2 is not your friend, and the levels (especially in closet grows) do build up to potentially hazardous levels. I run my fan for at least one minute before I head in for feeding/watering duties. If you don’t, you will notice a headache (as I foolishly did the first time I ran this thing) and from that point, you’re risking brain cells.
CONCLUSIONS, NOTES, MISC, ETC –
Let it run a bit and see how long it takes to blow through the loads. I’m averaging ten pounds every three to four days, which isn’t bad. My room is a 6x7x5 and the size/sublimation rate seems about right. I have not yet gone in with a PPM counter (though it is on my list) to get exact levels, however I am noticing happier, healthier plants throughout the lifespan (including veg). Temperature will increase or decrease your rates, so if you think your grow could use more CO2, you may want to reduce the amount of insulation on the vessel. If you want to maximize efficiency, add more insulation, or place the entire rig in a larger cooler and surround with ice. But at that point, I think the law of diminishing returns comes into effect. You should be spending your man-hours tending the plants, not the system. This things is cheap enough and foolproof (mostly) to make it worthwhile. There are many pros and cons to CO2, as well as limiting factors like soil, light, temp, genetics, etc, but if cost is one of yours, the Sublime Sublimator might be a viable solution. Either way, I humbly submit it to the cause. I'm not allowed to embed photos yet, but you can check out my gallery for the pics. If/when I get those permissions, I'll throw them into the body of the post.
For what it’s worth
-JunkWerks
Let me preface this by saying that the Sublime Sublimator is NOT A REPLACEMENT for commercial CO2 enrichment systems. There are, however, certain instances when a device such as this is damn useful. In some locations, bottled gas retailers are not conveniently located. Some of the more cautious (paranoid) folks don’t want to incur any security problems from obtaining bottled gas. Other people may be reluctant to add to the growing energy crisis by burning natural gas to create CO2. Still others (such as the creator of this tek and myself) live or work in places where dry ice(DI) is plentiful and cheap and/or free. He got his from the biology lab at the university. I myself didn’t even consider doing something like this until the local Vons started selling Penguin Brand Dry Ice. And even then, it was $1.00/lb which wasn’t very economical. But then we discovered that though it was priced per pound, it rang up as a barcoded $1.00 item. So as long as the “sale” on DI was going on, I was determined to capitalize on it. If you find yourself in a similar situation, I highly recommend giving DI CO2 enrichment a shot. And now, without further ado:
DIY Dry Ice CO2 Enrichment System, AKA "THE SUBLIME SUBLIMATOR"
Sublimation is the transition process from a solid to a gas. And left in the open air at average (65-75F) room temperatures, a five pound block of DI will completely sublimate in a few hours. The FAA conducted a detailed and thorough scientific study of DI sublimation rates. DI is used extensively in the air shipment of perishable goods, and they were looking into the hazards of CO2 buildup in an enclosed aircraft. The rates varied, depending on ambient temp/pressure, particle size, and insulation. Bottom line (and Chem 101 basics), the sublimation rate of DI can be extended by putting it into an insulated container. Add a small hole and connect a hose to it and bam – you’ve got a sublimator. Pretty simple eh? The Sublime Sublimator adds some technical refinements that make the system more efficient and easier to use.
--------------------------
PARTS LIST:
--------------------------
DRY ICE VESSEL –
The heart of the device, it should be insulated and AIRTIGHT. For my purposes, I hit up the Home Despot and grabbed a Bubba Keg 384 3-gallon beverage cooler/dispenser. $29. I like working with coolers like these because they’ve got holes pre-drilled. Gatoraide coolers might work, but the Bubba is choice because has an interlocking lid with a rubber seal built into the lid. If you can get your hands on a dewar or vacuum thermos bottle, that would be ideal. I picked the because it’s cheap and readily available, something the forums appreciate (I know I do).
HOSE QUICK CONNECTOR –
I used a 1/2 ‘’ nylon quick connector. $1.60. It has a built-in bushing and a rubber gasket. It’s also a compression fit which eliminates the need for brass wedges and Teflon tape. Most importantly, it will stand up to continuous removal and insertion of the hose (which we’ll get to later). Check the size of the valve. Look inside the cooler and you will see that there is a nylon hex nut that keeps the valve secured to the fitting. Unscrew this to determine what size you need. I even went as far as taking the nut to the plumbing section and dry-fitting it until I found the right size.
FEED HOSE –
10’ of 1/2” Polyethylene hose, available in the plumbing section. $5.99 It’s pretty durable, and has a thermal range good for our purposes. Avoid rubber, or polypropylene (aquarium hose) as it is not as thermally forgiving and can crack/degrade. There is an issue with C02 leaching plastics over time, but I’m told that this is not an issue. Apparently it takes a long time. I’ve cut my hose to a more manageable 5’ length anyway, so I have a spare if necessary.
INSULATION –
The Bubba Keg on its own provides some insulation, but not much. Certainly not enough to extend the life of a DI block beyond a day. My initial design for this was to put the DI in a Tupperware container until my friend turned me onto the Sublime Sublimator design. I found some R-6 foil backed duct insulation that works great. $6.00 If you have the space (I don’t in my setup) you could use exterior-grade R-30. If you do, please let us know how that works.
DISPERSAL FAN –
El cheapo-crapo $5.00 Wally-Mart special seems to work fine. I’m sucking enough power as it is, so I didn’t want to add to that tally by much. If you’ve already got an oscillating circulator fan in your setup, that will work just fine.
HANGING FISH SCALE –
I can only imagine how much money big box stores like Wal-Mart and Home Depot make off of people like us. This thing was about $5 bucks and registers all the way up to 50lbs, more than suitable for the amount of DI we’re sublimating.
TWO-PART EPOXY –
JB weld or the like. Just be sure that it cures fast and has a good thermal range in the lower end.
FOIL TAPE –
Nashua USED to make foil tape without a crummy Teflon backing to it. If you can find it, get it. Usually listed under “industrial” or “heavy duty”. If not, I suppose any tape will do. Foil is essential though, as it doesn’t react to temps as adversely as duct or electrical tape. DO NOT use masking, strapping, or packing tape. You’ll be sorry.
48” NYLON ZIP TIES –
We will use these to affix the insulation to the unit. Available in the electrical or plumbing section. Also nice to have on hand at work if someone asks you “Hey man, do you have any zip ties?” Tell them sure, and whip out the 4-footer. I guarantee they’ll never ask you for anything again.
CRAFT WIRE
GLOVES
A HAMMER
TOTAL COST: About $60
--------------------------
FABRICATION PROCEDURE:
--------------------------
STEP 1 – REMOVE KEG VALVE –
As I said before, there is a nylon hex nut that keeps the valve secured to the fitting. Remove this and the valve should simply unscrew. Toss the valve into your ever-expanding bonus part box. Keep the nut.
STEP 2 – INSTALL QUICK CONNECT –
The quick connect fitting should pop into the hole pretty easily. Now, Chinese manufacturing tolerances being what they are, you may find that the holes between the inner wall and the outer wall do not quite line up. This is fine, and one of the main reasons for the 2-part epoxy. When you have established the best dry-fit you can, break out the epoxy, mix it up, and smear the collar of the fitting liberally. Slide this into the hole and then screw on the nylon nut. Epoxy the nut to the inside as well and let the new assembly cure overnight. It is very important to get good epoxy seals, otherwise you will be losing precious CO2.
STEP 3 – SEAL THE LID VACUUM-RELEASE VALVE
Now, while your DI vessel is curing and you’ve still got some epoxy left, we can take care of that pesky vacuum release valve on the lid. Most beverage coolers will have a small hole drilled through the lid for this purpose, although on fancier systems they include a one-way gasket valve. Either way, that shit must go or your system will lose pressure. Epoxy the hole/valve and then place a strip of foil tape over it. Done and done.
STEP 4– AFFIX INSULATION
This is my favorite part of the operation because once it’s complete, the Sublime Sublimator looks less like some kludged K-mart shit and more like something NASA would build. Indeed it does resemble an onboard O2 tank. The best way to do this is to take the insulation, wrap it around the vessel, and let one edge overlap by a few inches. (Safety pro tip: Baby Powder your forearms and be sure to wear gloves and a longsleeve shirt you don’t mind tossing out afterwards. Cuz Fiberglass is fo-ev-a, yall.) Cut the insulation with large scissors or shears, and set aside the rest. Foil tape one side to the vessel and then wrap it carefully around. Have one of the big zip ties handy and affix the insulation with it. Don't cinch it tight. Remember, insulation works because it creates an inert gap between the container and the outside edge. Too much compression will reduce it's effectiveness. Use the remaining bit to create a square for the bottom. Foil tape the bottom piece to the side insulation..
STEP 5 – DRILL HOLE FOR SCALE
The scale is to help you determine how much DI you’ve got left in the tank. If you use the Bubba keg, a horizontally-drilled 7/16 hole will do fine. The load hook of the scale should slide easily through. Pressure should keep it from slipping out.
BRAVO! You have, in fact, “gotten her done”.
--------------------------
INSTALLATION AND USE:
--------------------------
ROOM SEALING –
Do your best to seal up the room. You might have already done this (I hope so) for odor control. Spray foam insulation, as well as caulk and DIY weatherstripping kits all work well for this. Big cracks are a no-no, so if you can see light with the door closed, you know where the leaks are. You will never get them all, but it makes little sense to go through all of this and not seal up the gaps. You will waste, time, money, and the CO2 destined for your plants will instead pollute the environment before it has a chance to be absorbed and converted into something more useful. Basically, what I’m saying is no half-assed hippie bullshit, if you please.
DI VESSEL PLACEMENT -
The vessel needs to hang in order to get a good reading of its capacity, so a floor beam or attic joist is good for upstairs/downstairs setups. A sturdy nail is good, a bolt is better. Just make sure that it’s secure. Closet and small rooms - hang from a high shelf or sit outside the room. Since the Sublime Sublimator is a passive system and will pretty much work no matter what, you can put the thing anywhere. But the best place is AWAY from any heat source. This especially includes ballasts and other electrical devices! The first few inches of the hose will be VERY COLD. Condensation and eventually ice will build up and drip onto anything nearby. You could insulate the feed if you like. My cement floor doesn’t mind a bit of water so I just let it drip. You also want it somewhere that you can get to conveniently for reloads, so factor that into your plan as well.
FEED HOSE -
Insert the hose into the quick connector and push. It should slide home snug. If you pull on it, it should not come loose. Run the hose from the vessel to the area behind your dispersal fan. A few inches above the fan works good. Secure it with wire or tape. Make sure that you have at least a foot or two of slack at the other end. Shorter hose lengths are more efficient, but longer lengths allow you to reload the system without removing the hose. Your choice.
LOADING THE DRY ICE -
Now comes the fun part. Once you have obtained your DI ( and I recommend 10lbs per load), set it aside. Disconnect the hose if necessary. Before you load the vessel, you’ll need to tare it out first. Hang it by the scale and note the reading. My approximate tare weight was around 5lbs. Take it down and unscrew the lid. For store-bought DI users you will need two 5lb bags. Take the first bag and drop it into the vessel. LEAVE THE ICE IN THE BAG. The plastic bag is a vapor barrier and slows down the sublimation rate. Don’t worry about the bag, it has holes in it and the CO2 will eventually escape. Now, with gloves and safety sunglasses in place, smash the second bag of dry ice to bits with the hammer, making sure not to destroy the bag in the process. Open the bag and dump the small pieces into the cracks around the large block. The idea is that the smaller pieces will help to lower the ambient temps of the vessel and slow the sublimation rate of the block. Either way, the CO2 is gonna wind up in your growing chamber, so no problemo.PLEASE BE CAREFUL WITH DRY ICE. It is colder and more dangerous than you may think. Always wear gloves when handling it or you will suffer burns!!!
LEAK-PROOFING AND HOSE TEST –
When the system is loaded to the brim, take a few ounces of warm water and pour it onto the ice. WOW, SCIENCE! Everybody has seen this effect before. You are creating dense H2O/CO2 fog that makes rockstars look hella cool and will allow you to test the integrity of your seals. Put the lid on quickly and lock it down. You should see some of the vapor escaping the seal, once again, Chinese tolerances will kill us all. Place a band of foil tape around the lid gap and that should seal the thing tight. Now if you look at the opening or the end of the hose, you will see the vapor pouring out. Cover your finger over the hole for a moment (it won’t hurt you) and check for any other leaks. Patch with foil tape as necessary. You should not have any leaks around the epoxy area. Connect the hose back and hang the vessel once again. The new weight minus the tare will give you your total C02 load (in this case, around 10lbs). MAKE NOTE OF THE TIME! This is a crude system, but we can still calculate approximate sublimation rates. Check your grow chamber and make sure that the hose is connected to the fan intake properly. That’s it.
FAN CYCLES AND SAFETY –
You should already be running an exhaust fan. Even with CO2, venting is essential for growth and temperature control. There are a variety of ways to vent things and I’m sure you have read them all so I won’t go into it here. Just be sure that you switch any continuous fan to run periodically instead. I myself invested $70 in a short cycle timer and I have it run on a 5minute on/4 hour off cycle. The CO2 will be constantly building up, unlike valved systems, so this scheme works just fine. You can play with your fan timers. The less they run, the more CO2 your plants will have. SAFETY PRO TIP – Purge your grow chamber before working inside it! CO2 is not your friend, and the levels (especially in closet grows) do build up to potentially hazardous levels. I run my fan for at least one minute before I head in for feeding/watering duties. If you don’t, you will notice a headache (as I foolishly did the first time I ran this thing) and from that point, you’re risking brain cells.
CONCLUSIONS, NOTES, MISC, ETC –
Let it run a bit and see how long it takes to blow through the loads. I’m averaging ten pounds every three to four days, which isn’t bad. My room is a 6x7x5 and the size/sublimation rate seems about right. I have not yet gone in with a PPM counter (though it is on my list) to get exact levels, however I am noticing happier, healthier plants throughout the lifespan (including veg). Temperature will increase or decrease your rates, so if you think your grow could use more CO2, you may want to reduce the amount of insulation on the vessel. If you want to maximize efficiency, add more insulation, or place the entire rig in a larger cooler and surround with ice. But at that point, I think the law of diminishing returns comes into effect. You should be spending your man-hours tending the plants, not the system. This things is cheap enough and foolproof (mostly) to make it worthwhile. There are many pros and cons to CO2, as well as limiting factors like soil, light, temp, genetics, etc, but if cost is one of yours, the Sublime Sublimator might be a viable solution. Either way, I humbly submit it to the cause. I'm not allowed to embed photos yet, but you can check out my gallery for the pics. If/when I get those permissions, I'll throw them into the body of the post.
For what it’s worth
-JunkWerks
Last edited:
