co2/flowering

[Gobwats]

I think the tank ended up only lasting about 2 weeks. I dont know if I was using to much not enough. Does any one know how long i should expect a 20 lb. tank to last. I dont want to waste it but then again what is 20 dollars every 2 weeks. I could live with that. I wish i had a way to measure the co2 ppm in the room. I need to invest in a co2 monitor and controller. That would make things so much easier.

You should be seeing more than 2 weeks from a 20# bottle unless you have n extremely large area; the formula posted at Hydrofarm is very good for figuring out the flow rate and duration you need for the volume that you are adding the juice to. My last 20# bottle lasted just shy of 9 weeks, and that was keeping a DR80 (32"x32"x5' basically) at 1700ppm. You can buy a syringe type test kit where you pull the sample through a special tube (new tube required for each test = about $5 a pop) but I just trust the formula and listen to my plants. If you are going through a 20# bottle in 2 weeks time in a small space (<100cuft) then you are probably giving them too much and could be getting some down into your reservoir causing the wild pH drops (been there before as well.) Measure the volume of the space you are growing in (wxdxh) figure out how high you want to elevate the concentration (keeping in mind that the benefits taper at around 2000ppm and it becomes toxic) then set your flow meter/timer accordingly. Eventually I hope to have mine running on a fuzzy logic controller, until then I'll keep doing the math.

 

[Ganjagrower1]

thanks Gobwats i am going to pick up a co2 tester here soon but for now i will try to find the area that i am growing in and see where i should have the flow set to. if i did it right my area is 8x4x7....... 8ft wide 4ft deep and 7 feet tall. so from my calculations i should have 224 cuft. let me know if i did this right. if i am right i went to the hydrofarm web site and i did the flow rate calculator and it says to put my flow rate at 0.54 cft hour. so i am going to check my flow rate and see if i am to high.

 

[Ganjagrower1]

OMG they are starting to smell dank as hell and the crystals that are packing on. They have massive white hairs. I am looking forward to the end results of this grow being that i added co2 and a few different additives.

 

[loco81]

well wheres the pics lol

 

[Ganjagrower1]

well i went down to my local circuit city for the big sale to try to get a macro lens for my digital cam. and they were all gone so i can going to try another one and going to keep my fingers crossed. My cam wont let me get that close. I am going to have to dial in the cam before i can up close and see the crystals but i assure you i will put up some new photos soon.

 

[loco81]

lol better then my camera phone i got some new pics of my room now looks a lot better will post pic soon as i can

 

[Ganjagrower1]

right on loco looking forward to the photos. My ladies are loving there new surrounding as well.

 

[Ganjagrower1]

ok i have a question my fan leaves are starting to turn yellow and they have brown spots on them. does any one know what this could be without a pic of it. I will get a pic later and post but for now i have to wait for the pic.

 

[moses224]

guys quick question...what type of store do you fill at.... i have to go to grow store and swap out its 20 a tank......im curious if theres a better way?????

 

[xcrispi]

Gobwats is spot on w/ your ph dropping = too much CO2 .

Moses - look around town for a welding supply store , might not look as suspicious . But the prices are about the same , and most still swap tanks unless you have all day to wait while they refill your own . Only other option is a CO2 generator and they create tonsa heat .
Crispi

 

[Ganjagrower1]

I fill my tank at a welding supply place. I just take my tank in and they fill it while i am there and it is only 20 dollars to fill.

 

[moses224]

awsome i just called and i got one right up the road.....great advice much props....you say the generators generate alot of heat??? i thought they only ran 6 minutes an hour based on a 6cf one. That said i was told it wouldn't generate allot of heat. In my new setup i was going that route so i didn't have to swap but if it does generate substantial heat ill just use my 50lb and have it filled at store.....

 

[Ganjagrower1]

ok now is it ok to add cal mag to gh flora series bloom and micro because it looks like i have a deficiency. I will post pics later when lights are on. but the most important thing is do i need to use cal mag with tap water and i am using micro for hard water.

 

[Ganjagrower1]

ok so i went a took a couple of photos so you can see what i am talking about with the leaves.

You can kinda see it on the big fan leave the yellowing.

 

[moses224]

h0w man weeks into flower are you? could just be regular N deficiancy...oh just read brown spots on leaves..those spots would be PH imo.

Use this its and OG tool
Nutrient Disorder Problem Solver
Version 1.1 - Feb. 1998 - distribution okay

To use the Problem-Solver, simply start at #1 below. When you think you've found the problem, read the Nutrients section to learn more about it. Diagnose carefully before making major changes.
1) If the problem affects only the bottom or middle of the plant go to #2. b) If it affects only the top of the plant or the growing tips, skip to #10. If the problem seems to affect the entire plant equally, skip to #6.
2) Leaves are a uniform yellow or light green; leaves die & drop; growth is slow. Leaf margins are not curled-up noticeably. >> Nitrogen(N) deficiency. b) If not, go to #3.
3) Margins of the leaves are turned up, and the tips may be twisted. Leaves are yellowing (and may turn brown), but the veins remain somewhat green. >> Magnesium (Mg) deficiency. b) If not, go to #4.
4) Leaves are browning or yellowing. Yellow, brown, or necrotic (dead) patches, especially around the edges of the leaf, which may be curled. Plant may be too tall. >> Potassium (K) deficiency. b) If not, keep reading.
5) Leaves are dark green or red/purple. Stems and petioles may have purple & red on them. Leaves may turn yellow or curl under. Leaf may drop easily. Growth may be slow and leaves may be small. >> Phosphorus(P) deficiency. b) If not, go to #6.
6) Tips of leaves are yellow, brown, or dead. Plant otherwise looks healthy & green. Stems may be soft >> Over-fertilization (especially N), over-watering, damaged roots, or insufficient soil aeration (use more sand or perlite. Occasionally due to not enough N, P, or K. b) If not, go to #7.
7) Leaves are curled under like a ram's horn, and are dark green, gray, brown, or gold. >> Over-fertilization (too much N). b) If not, go to #8…
8) The plant is wilted, even though the soil is moist. >> Over-fertilization, soggy soil, damaged roots, disease; copper deficiency (very unlikely). b) If not, go to #9.
9) Plants won't flower, even though they get 12 hours of darkness for over 2 weeks. >> The night period is not completely dark. Too much nitrogen. Too much pruning or cloning. b) If not, go to #10...
10) Leaves are yellow or white, but the veins are mostly green. >> Iron (Fe) deficiency. b) If not, go to #11.
11) Leaves are light green or yellow beginning at the base, while the leaf margins remain green. Necrotic spots may be between veins. Leaves are not twisted. >> Manganese (Mn) deficiency. b) If not, #12.
12) Leaves are twisted. Otherwise, pretty much like #11. >> Zinc (Zn) deficiency. b) If not, #13.
13) Leaves twist, then turn brown or die. >> The lights are too close to the plant. Rarely, a Calcium (Ca) or Boron (B) deficiency. b) If not… You may just have a weak plant.

The Nutrients:
Nitrogen - Plants need lots of N during vegging, but it's easy to overdo it. Added too much? Flush the soil with plain water. Soluble nitrogen (especially nitrate) is the form that's the most quickly available to the roots, while insoluble N (like urea) first needs to be broken down by microbes in the soil before the roots can absorb it. Avoid excessive ammonium nitrogen, which can interfere with other nutrients. Too much N delays flowering. Plants should be allowed to become N-deficient late in flowering for best flavor.
Magnesium - Mg-deficiency is pretty common since marijuana uses lots of it and many fertilizers don't have enough of it. Mg-deficiency is easily fixed with ¼ teaspoon/gallon of Epsom salts (first powdered and dissolved in some hot water) or foliar feed at ½ teaspoon/quart. When mixing up soil, use 2 teaspoon dolomite lime per gallon of soil for Mg. Mg can get locked-up by too much Ca, Cl or ammonium nitrogen. Don't overdo Mg or you'll lock up other nutrients.
Potassium - Too much sodium (Na) displaces K, causing a K deficiency. Sources of high salinity are: baking soda (sodium bicarbonate "pH-up"), too much manure, and the use of water-softening filters (which should not be used). If the problem is Na, flush the soil. K can get locked up from too much Ca or ammonium nitrogen, and possibly cold weather.
Phosphorous - Some deficiency during flowering is normal, but too much shouldn't be tolerated. Red petioles and stems are a normal, genetic characteristic for many varieties, plus it can also be a co-symptom of N, K, and Mg-deficiencies, so red stems are not a foolproof sign of P-deficiency. Too much P can lead to iron deficiency.
Iron - Fe is unavailable to plants when the pH of the water or soil is too high. If deficient, lower the pH to about 6.5 (for rockwool, about 5.7), and check that you're not adding too much P, which can lock up Fe. Use iron that's chelated for maximum availability. Read your fertilizer's ingredients - chelated iron might read something like "iron EDTA". To much Fe without adding enough P can cause a P-deficiency.
Manganese - Mn gets locked out when the pH is too high, and when there's too much iron. Use chelated Mn.
Zinc - Also gets locked out due to high pH. Zn, Fe, and Mn deficiencies often occur together, and are usually from a high pH. Don't overdo the micro-nutrients-lower the pH if that's the problem so the nutrients become available. Foliar feed if the plant looks real bad. Use chelated zinc.
Check Your Water - Crusty faucets and shower heads mean your water is "hard," usually due to too many minerals. Tap water with a TDS (total dissolved solids) level of more than around 200ppm (parts per million) is "hard" and should be looked into, especially if your plants have a chronic problem. Ask your water company for an analysis listing, which will usually list the pH, TDS, and mineral levels (as well as the pollutants, carcinogens, etc) for the tap water in your area. This is a common request, especially in this day and age, so it shouldn't raise an eyebrow. Regular water filters will not reduce a high TDS level, but the costlier reverse-osmosis units, distillers, and de-ionizers will. A digital TDS meter (or EC = electrical conductivity meter) is an incredibly useful tool for monitoring the nutrient levels of nutrient solution, and will pay for itself before you know it. They run about $40 and up.
General Feeding Tips - Pot plants are very adaptable, but a general rule of thumb is to use more nitrogen & less phosphorous during the vegetative period, and the exact opposite during the flowering period. For the veg. period try a N:K ratio of about 10:7:8 (which of course is the same ratio as 20:14:16), and for flowering plants, 4:8:8. Check the pH after adding nutrients. If you use a reservoir, keep it circulating and change it every 2 weeks. A general guideline for TDS levels is as follows:
seedlings = 50-150 ppm; unrooted clones = 100-350 ppm; small plants = 400-800 ppm; large plants = 900-1800 ppm; last week of flowering = taper off to plain water. These numbers are just a guideline, and many factors can change the actual level the plants will need. Certain nutrients are "invisible" to TDS meters, especially organics, so use TDS level only as an estimate of actual nutrient levels. When in doubt about a new fertilizer, follow the fertilizer's directions for feeding tomatoes. Grow a few tomato or radish plants nearby for comparison.
PH - The pH of water after adding any nutrients should be around 5.9-6.5 (in rockwool, 5.5-6.1). Generally speaking, the micro-nutrients (Fe, Zn, Mn, Cu) get locked out at a high pH (alkaline) above 7.0, while the major nutrients (N, P, K, Mg) can be less available in acidic soil or water (below 5.0). Tap water is often too alkaline. Soils with lots of peat or other organic matter in them tend to get too acidic, which some dolomite lime will help fix. Soil test kits vary in accuracy, and generally the more you pay the better the accuracy. For the water, color-based pH test kits from aquarium stores are inexpensive, but inaccurate. Invest in a digital pH meter ($40-80), preferably a waterproof one. You won't regret it.
Cold - Cold weather (below 50F/10C) can lock up phosphorous. Some
varieties, like equatorial sativas, don't take well to cold weather. If you can keep the roots warmer, the plant will be able to take cooler temps than it otherwise could.
Heat - If the lights are too close to the plant, the tops may be curled, dry, and look burnt, mimicking a nutrient problem. Your hand should not feel hot after a minute when you hold it at the top of the plants. Raise the lights and/or aim a fan at the hot zone. Room temps should be kept under 85F (29C) -- or 90F (33) if you add additional CO2.
Humidity - Thin, shriveled leaves can be from low humidity. 40-80 % is usually fine.
Mold and Fungus - Dark patchy areas on leaves and buds can be mold. Lower the humidity and increase the ventilation if mold is a problem. Remove any dead leaves, wherever they are. Keep your garden clean.
Insects - White spots on the tops of leaves can mean spider mites
underneath.
Sprays - Foliar sprays can have a "magnifying glass" effect under bright lights, causing small white, yellow or burnt spots which can be confused with a nutrient problem. Some sprays can also cause chemical reactions.
Insufficient light - tall, stretching plants are usually from using the wrong kind of light.. Don't use regular incandescent bulbs ("grow bulbs") or halogens to grow cannabis. Invest in fluorescent lighting (good) or HID lighting (much better) which supply the high-intensity light
that cannabis needs for good growth and tight buds. Even better, grow in sunlight.
Clones - yellowing leaves on unrooted clones can be from too much light, or the stem may not be firmly touching the rooting medium. Turn off any CO2 until they root. Too much fertilizer can shrivel or wilt clones - plain tap water is fine.



HOPE THAT HELPS

 

[ninjaboy28]

be carefull with your co2 during flowering it caused my last grow to have very strechy plants. i mean that they continued to veg a bit during flowering. overall my co2 helped out alot during my grow , but towards the end i shut it off completly(your yellow leaves on top of your plant apear to me as co2 burn) i'm no expert but have used your same set up for 3 grows now. peace-the billman

 

[Ganjagrower1]

ninjaboy i dont have any problem with stretching. they did that all right in the beginning couple or weeks. now they are just packing on the weight. it could of been a couple of thing that happened with the fan leaves. maybe ph it dropped down to 3.6 for some reason. now i have it right where i want it. Things are starting to look good except for the yellowing on the leaves. other then that they are blooming just like they are suppose to. I think on my next grow i am going to change out my nutes from gh flora series to another nute. I think i am going to go with a dutch master line. I was hearing nothing but good things about the gold line. does any one know about dutch master gold i would like to know how well it works. and has any one used gh then changed to dm and seen much of a differencs.

 

[moses224]

What does c02 burn look like?

 

[Ganjagrower1]

i am not sure i was told i might have co2 burn. this is my first time using co2 and i have never had any deficiency any other grow. so not really sure i am about 35 days in now.

 

[moses224]

I have some leaves that look like nute burn but I KNOW MY NUTE REGIMENT IS RIGHT. I went thru a 20lb tank in 4 days based on 500ppm running every fifteen minutes only when lights where on wonder if i had leak and in turn thats why some fan leaves yellowed like nute burn