okay so I have 8 rooted clones, I put the rooted clones in tubs (4 in each). its a top feed system and I cannot get the plants to grow. I am supposed to start week two of the nutes today and I am weary of doing so since they have no new growth on them. The clones are pineapple kush. They were moved from the humidity dome to the tubs a week ago. any suggestions or thoughts on this??
I was having a very Similar issue and figured out that my RH in the veg area was far too low. If your temps are around 75 in the veg area you need like 70% humidity, ideally. My rh was around 25 and it completely stunted growth. The day after I rigged up humidity domes for my veg buckets, new growth started immediately. So tell me, what is the temp / RH in your veg area? Very informative, VPD; http://www.just4growers.com/stream/temperature,-humidity-and-c02/vapor-pressure-deficit-the-hidden-force-on-your-plants.aspx (I put asterisks where I want you to read) "Plants cope with changing humidity by adjusting the stomata on the leaves. Stomata open wider as VPD decreases (high RH) and they begin to close as VPD increases (low RH). Stomata begin to close in response to low RH to prevent excessive water loss and eventually wilting but this closure also affects the rate of photosynthesis because CO2 is absorbed through the stomata openings. ***Consistently low RH will often cause very slow growth or even stunting***. Humidity therefore indirectly affects the rate of photosynthesis so at higher humidity levels the stomata are open allowing co2 to be absorbed."
Did you even glance over that Webpage? Or just throw out what you think is optimal? Take a look at the chart.
did you just google "good humidity levels for growing?" or did you think about this a little further before posting a website that makes, in my opinion, pretty generalized claims. For the record, you CAN have humidity up to 70 percent in vegetation, without much harm. But I wouldn't consider it optimal. and in flowering an RH that high is a serious no-no. you're almost guaranteed mold at that stage. but, the OPs concern was with it in vegetation. First, in not one paragraph of that article did they reference cannabis. Second, the variation amongst different cannabis strains is pretty diverse. you can have something like an equatorial sativa, that would be pretty happy with 60-70 percent humidity, but you also have indicas, which originated out of deserts, mountains, and high deserts, for that matter. so its very strain dependent. Third, experience has shown me 70 percent is too high. the lower the humidity, the quicker plants take up water this is true. in hydroponics, one could even speculate that this means they are also taking up nutrients at an accelerated rate, resulting in quicker growth. most growers that I've found, are plenty happy with 40-60 for their whole cycle. so, no, I didn't just throw it out there. my RH has gotten down below 30 before with no issues.
I never said anything about flower in those ranges. My flower is at 76f 36rh. Secondly, of course people would be happy with 40-60% rh, more so 60 in veg, 40 in flower. I wasn't looking for an argument, btw.. but trying to help someone in a similar situation. Glad you stopped by for the additional input. Edit: OP, Keep that RH sky high in veg
..within my experience, I don't see "sky high" RH levels in veg (or any stage) as being of any benefit .. On the higher end during initial growth yes 60-65%, but anything higher than that is over kill... Again, strain specific...
My veg room is 75F @50% RH , I'm having the best luck with a bubble cloner. It has made me decide to grow hydro till I can go outdoor for summer.
It gets very dry in my house in the winter. My rh in the grow room is usually 20-30%. I have excellent grorth rate veg through flowering with very good yields and results. I have experimented with adding humidity but found it difficult to maintain a higher rh (tried several humidfiers and misters). I have never experienced "slow growth" due to my rh levels, though I'm sure it could cause a problem if severe enough. I don't buy the theroy that your clones are not showing growth due to the rh. My clones take a good month or so from the time taken to show veg. growth as all their energy is going into building a root mass to support the plant. 70% needed is just ridiculous.