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  • #21
Really nice set-up Varun, I have a few things to suggest:

Take out any access/side panels and open the chamber up as much as possible and turn off the fans!
Then you can try one fan for abit and see and slowly put back some of the glass and see, my plants are essentially in the open and they love it! Humidity can be around 50% or less for the HLers.

Definitely add more lights! I have 6 T12 fixtures for 12 tubes over my HL chamber and I have plenty of distance between them and the plants, but not as much distance you have there.

If that's a window above the tanks, I'd have them open as much as possible, spring/fall. Fresh air is good. Very good.
I AC in the Summer (2 mos) just to keep them from getting over 80F for too long. It's like maybe down to 70F at night. Temperature is not just numbers though...

Winter is pretty chilly rarely getting 70F and down to like 48F at night for a couple of months. Spring & Fall are their favorite... but it works overall. I've had healthy plants for years and the Sphag is extremely happy there and I only water like once every 3 days or so and that's the only time I mist as well with a hand sprayer.

Hope this helps!
 
  • #22
Hi guys,

thanks for taking the time to care and offer suggestions.

I used to use a ultrasonic humidifer, but since I have limited RO water which I mostly use for the mistking system, I have to be a bit careful and cannot use it with the ultrasonic humidifier. SO I used to use tap water .. hence the mineral buildup on plant leaves. Currently I do not use any fan to blow air off the lights. Becos there is no gap where I can outfit a fan to blow over the lights.

Night time temps in old setup usedto be high 60s in the summer. Mostly thanks to multiple ice packs. nOw i can't use icepacks. The tanks are too tall.

Hi ROn! Yes! I definitely understand the geometric decrease of light intensity. Believe me! thats why I bought a bay of 4 54watt tubes. Initially a single 2 x T8 along with a supplimentary CFL used to light everything in my old setup and that was enough. but yes...at a closer distance. TO consider th distance, I spent money for this light setup. Now I am considering selling it and probably trying a 6 tube bay or a metal halide...altough I am wary as Tony says they get really hot.

TOny...would u suggest to get rid of the T8 fixture. I think its pretty useless at this distance. Replace it with the CFLs as u mentioned? As u say...MH can get pretty hot. I want to avoid that if possible.

Guys...I just repositioned the sensor which was earlier near the pot level to the level of the plant body itself. HOLY!! Temps that were before 72F were now 79F. Clearly temps are dramatically higher at foliage level. THis means during the summer temps were over 90F for the most time.

I was considering the exact swords setup u mentioned. I even have the fans ready..but was putting it off to see if I can somehow prevent all that ducting and just push in room air into the tank.

Thanks for the comments Quogue. You are right. I removed the side glass and wow...temps droped at plant level by 5-8F. Window is sort of open...I turn on the fan in it at night to bring in cool air and drop temps to 62 or 58F lowest during autumn (now). I imagine it will only get lower and can go to 40s in winter.

Clearly...I need to run tests with:

1) water quality
2) heat...check at other places in tank...plant foliage level
3) put back hte glass I had..and re-check temps
4) Buy some CFLs and replace those useless T8s (at this distance)

anything else u guys would suggest to do as the first priority. I think more than anything...its the temps that are issue now.

Once again...thanks everyone. I really appreciate your feedback. I'll keep ya all updated.

varun
 
  • #23
You can remove the sides! I didn't know that! You should be able to get a good air flow through the tank that way. Removing hot air out the top allowing cool air to be drawn in through the side. If you use fans place them at the top blowing air out the top. You should see even greater drop at plant level.

CFL might be a good choice. They run hotter then T8's but are not too bad. You might be able to find a small one that fits in the tank.
 
  • #24
well..not the whole sides. On the side...the tank has an opening. its like the TOP 1 and a half foot of glass can be folded down on a hinge. So unfortunately, tis not the bottom.

Well...biggest thing about T8 is that at htis distance...they probably are useless. :( Damn!! was a shocker to see the temps soo high. I mean that could make a lot of sense to the issues I was having in summer. If pot level was like 85F or so...i am sure the plant level was like atleast 95F or so. damn!!
 
  • #25
TOny...would u suggest to get rid of the T8 fixture. I think its pretty useless at this distance. Replace it with the CFLs as u mentioned? As u say...MH can get pretty hot. I want to avoid that if possible.

Maybe..

This would only be a benefit if you were to replace them with more overall wattage. CFL do run at a higher output than T8 and the compact nature allows more bulbs. So they are more effective at longer distances. Not sure about the feasibility due to the rather narrow long space the T8 is currently taking up. Large sized CFL tend to be rather bulky. Maybe a series of smaller CFL.. But that would probably require a homemade light fixture. How much space do you have up there? I have seen other setups with alot of height and there would be lights down the sides to get more light at the plant level.

My other question though. Is why so tall? Are you planning to have some tall plants and some short plants in the end? If not then why not just reduce the height for now to get the lights closer. It does look nice tall though so I can see the asthetics.

What you need is like 4 of these babies! http://www.grow-light.com/LED-Grow-Light-Purple_p_1911.html

On the heat issue.. I would have glass between the plants and the lights to block the heat. I would have the top sides open a bit to allow air in and more heat out. Let the heat from the lights go up on it's own. Warm air inside the grow chamber can exhaust through the top sides on it's own. Plants do not need 'fresh air' Without a vent at the bottom for air exchange you are only pumping heat from the lights down onto the plants with all those fans at the top. Even by aiming a fan upward you are sucking air down on the other side and with it heat from the lights. Shut them off. All you need is a very small fan circulating air horizontally at the plant level. You can play around with the sides open/glass over the top between the lights but in either case I would not be running the fans at the top at all.

In fact this type of setup could work very well tall so that you have enough height on the sides to hold moisture around the plants, but still have an open top to run hotter high power lights with minimal heat buildup because the top is open and there is little mixing between the hot air above and cool air below.
 
  • #26
Smaller cfls are less efficient then big ones.
 
  • #27
Why not just get another set of T5HO?????
 
  • #28
Hi guys,
SOrry for late reply. Grad school is very very hectic in these opening weeks of the fall semester.
Don't really have too much space up there. Probably the only room I have is the width of a regular 2 tube 4' T8 or T12 fixture. I definitely can don't know how to get lights on the sides without it being a major hassle...plus, I want plants to grow towards the top...not lean ito the side
The only reason why I had the tank soo tall is because I knew that nepenthes grow tall and given good conditions, they rapidly grow tall and hit the top of the tank. This is especially true for most sumarta species like aristolochioides, glabrata etc. For instance, thats exactly what Ihappened to my glabrata. Now the aristo is nearly 3' tall.
LOL!! that LED will cost me a kidney to buy enough of those. :p
GOod to know about the fans. I understand what you mean. Its a cyclic rotation of air that pulls in from the top back to down and back up. I am thinking of a way to solve the issues you guys have all brought up. Firstly, I will openup the sides. One fan at the top pulling air out. THen one fan at the bottom plant level so circulating bottom air. The only issue now is lighting.
I don't mind Delwin's idea. But do u guys think a couple more 54watt T5 will do the trick? That would be a 100$ more and overall of 6 54 watt T5. Do u think that will be enough Tony? ANy other guys here who use this set of lights for this distance? ALso what if I use mylar and cover up all sides and even the front during normal running time of the tank?
thanks,
V
 
  • #29
Mine is 3feet tall.Only T5HO is able to go that deep. As for MH, forget it, it produce far too much heat. Unless you want to waste your kidney for the LED:0o: You can fix something like a stand maybe a piece of glass block on each end of the light set to make some space between the light and the top glass. The place a pc fan at a corner to blow away the heat produce from the lights.
 
  • #30
If you can swing the 2tube 54w T5 I think it would be worth replacing the other yes. The mylar is a good idea. You are losing alot of light out the sides because of the distance and fluorescent bulbs are not very directional, scatter light every which way.

I still feel your excessive moisture loss is the biggest problem. Much more so than the lighting and temperature issue. I also still think the fans are contributing to the heat problem. You also never mentioned (unless I missed it) the room temperature during the day when you say it is getting up into the mid80s or low 90s inside the grow chamber? This seems like a rather important bit of information to help understand just how much warmer the grow chamber is running over the ambient room temperature. Some rise is expected but just how much are you experiencing?

I am curious to how things go with changing the fan set up. Have you tried simply turning the fans off during the day and monitoring the temperature down by the plants?
Examine closely how your fans are blowing/pulling air in or out of the chamber. If air is exiting the grow chamber then it must be entering somewhere else. If the air entering is not cooler humid air than what's inside the grow chamber already, then it is hurting not helping. It is much more stressful on the plants to have excessive transpiration vs. warmer than optimal temperatures.
 
  • #31
The temperatures are as follows:

Summer (Room)
Max: 88-90F
Min: 70F
SO far, I have been noticing that in the tank the probe was at the pot level and temps were like 5F lower or normalized at 85F. I thought that was just the buffer effect of water and the fan. But considering the air temp in the tank is a lot higher and the gradient just above the plants is soo much hotter, I wouldn't be surprised if it hit over 95F in the tank on the hottest days.

Current temps (autmn is coming) Readings from today
Max: 82F
Min: 62F

In tank, temps appear to be: Max: 78F and min: 59F

Unfortunately, as i mentioned, The probe was incorrectly placed durin the summer season. So perhaps, I am waaay off with the temp readings.

And you are right, ever since I removed one fan from the inside, I had to water only once in the week. There is still one fan at the pot level. I will raise it up and put it at plant level. The only concern is that Wouldn't that dry out the plants? Where exactly do u think is a good position. And bear in mind, I cannot control fan speed. (Atleast, without any other electronic devices)

There is no opening for the tank anywhere apart from the top and the side door. It is otherwise sealed at the bottom. So that means, the only air circulating is from the top where the lights make it hot.

But you guys say fresh air is not needed? Wouldn't a lower CO2 concentration in the air make it unfavourable for plant growth? But yes, I understand that without correct conditions and excess heat, that would be an even bigger issue.

So do u think I should turn off all the fans tomorrow and take readings?

cheers,

V
 
  • #32
Reading of your struggles to get things right makes me feel better about my same struggles. It's like trying to balance on basketball while juggling! Just when I get one parameter right, it throws another off.
 
  • #33
Wow that hot in your room? Think you need to address that or you will never have cool temperatures in your grow chambers without actual refridgeration!

I would leave the lower fan as is and try shutting off the upper fans for a day and see what happens. All you need is gentle moving air around the plants. If the fan is below the pots I am sure there is some air moving among the leaves also. Low CO2 levels are only a minor concern. CO2 levels go up during the night so there is plenty of CO2 for the plants during the day. I have had cutting root and grow in totally sealed ziplock bags for months on end without any problem. The need for fresh air is way over exaggerated. Stale air however is a problem. Plants need some air movement to promote normal transpiration and gas exchange.

Just a FYI, my greenhouse in the Summer can easily hit the upper 80's during the day. Highland/ultrahighland plants don't mind the warmth during the day as long as the humidity is decent. The critical part is that they cool off at night to slow their metabolism and preserve the sugars they made during the day. 70 at night is too warm.

Not sure what else to offer, I think we have addressed the light issues and the excessive drying but without either cooling the room big time or cooling the grow chamber directly, I think you will be fighting a losing battle during the Summer with the dsy and night time temperatures. In all reality even 62 at night is a bit on the warm side for many of plants you have. My only solution to that without making major changes to actively cool things down, is to select plants which prefer warmer temperatures.
 
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  • #34
Unfortunately It definitely is the apartment. I live on the 15th floor and my apartment windows face the east. So right in the morning, no matter how much it has cooled at night, temps increase drastically as pure sunlight just warms everything up. Currently, for instance, its 1PM in the afternoon and temps are:
79F in the room
75F in the tank. Water vapor is acting as a great buffer.

Night time mins were
62F in room
60F in the tank ( I keep that fan in the window pulling air in. I can feel the air is a lot cooler...I need to duct that air into the tank and the fan to come on only at night....probably witha humidifier.

Well...during the summer... I did use the air conditioner once in like 2-3 days...mostly duringweekends whenever I was in the apartment. So I am probably sure that is why the plants still look as decent they are. I just can't afford to run the air con at all times of the day. I just simply can't. SO I saved it and used it during night time only. Winter will be a joy as I just need to open the window at night and temps will be low 50s or high 40s in a matter of minutes in the tank. I am going to work on the ducting so that I can feed cold air in and a humidifier inlet so it is cold humid air.

I am consideriing moving into a air conditioned apartment for next summer. So I guess that is now established after the results i have gotten this summer.

---------- Post added at 05:16 PM ---------- Previous post was at 05:14 PM ----------

Reading of your struggles to get things right makes me feel better about my same struggles. It's like trying to balance on basketball while juggling! Just when I get one parameter right, it throws another off.

That is exactly how it is mate. Increase air circulation = lower humidity. Increase humidity = hot air accumulating. I need almost like two wind patterns in the tank that are almost independent. One at the bottom,one at the top.
 
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