indoor hydroponic Lettuce

[hermit825]

Hi All!
I would like Opinions on several things actually, I am in Fairbanks Alaska, and will be dealing with a mighty cold winter environment.... a traditional greenhouse is out, so I will be using a standard office space, and plan to purchase crop kings 10-36 nft system, and their single tray microgreens system and plumb them together, under 100% artificial lighting, and producing several cultivars of lettuce, and the system comes with the fertroller nutrient injections system, but I like the intelliclimate grow room controller, are they compatible?
I am hoping that 16 ea 400w HO flourescents will be adequate to cover a 15 1/2' x 26' grow area...
with this setup, what problems might I most likely encounter?

THANKS!!
Bill

[rainbowgardener]

This stuff is all very technical (as witness your post which reads like Greek to me ). I don't think we have a lot of hydroponics folks around the forum, because I have seen other posts similar to yours go unanswered.

Possibly someone will come by with the expertise to answer your question, but if not, I'd suggest that you look for a good book or even better some kind of hydroponics society near your where you could talk to people who are actually doing it.

In the meantime 15 x 26' is huge, you could grow enough lettuce to feed most of the population of Alaska. Are you growing something besides lettuce? As noted I don't know ANYTHING about this stuff, but just as a general gardener who starts seeds under lights in my basement, 16 fluorescents doesn't sound like enough to me for that big an area....

Good luck with your worthy endeavor!

[hermit825]

Thanks for your input, I will continue to seek advice, I have been moitoring several websites, and have concluded that you never know until you try! hehe BTW, the 16 lights will be the 4 footers...hope its enough space, just cant see being cost effective going with HPS.....


Thanks again!

Bill

[rainbowgardener]

I figured you meant 4' tubes. I have 12 of them plus a couple 2' long for my seed starting operation that is 2' wide by 16' long. If you are talking about regular fluorescent tubes (I don't know what the HO means) they need to be just a few inches above the plants, which limits the area the light will cover...

[opabinia51]

Yes, hydroponics are very finicky. If you get a fungal infection your entire crop will be lost. Also, you be stuck with using chemical fertilizers for the system which add very little flavour to the vegetables (in this case lettuce.)

A better bet would be to set up some shelves with grow lights and buy some potting soil and if they have it some compost as well as some manure and grow your plants indoors with the grow lights in pots. A lot cheaper,and not nearly as much hassle, and a tonne more flavour.

[hermit825]

Oic... thats kinda what I was figuring, I hope I am not off.. Ive been looking at the Hydrofarm 8 Lamp 6500K T5 Fluorescent Grow Lights, I have also been looking into the "light movers" but not too sure on their reliability....

[JONA878]

Hi Bill.
I've never grown lettuce under hydroponics or artificial lighting before so would be very interseted in your results.
I used to grow a quarter acre winter crop under glass but with no additional light. Here in the south of England the light was ok....just took the plant two - three extra weeks to mature a good head.
Do you have to have some form of darkness period to stop bolting or are there varieties that will stand 24 hr lighting.
As it seems to me that the light time may be the most critical in holding the plant.
The other problem in such an enclosed area may of course be mildew.

Jona.[color=green][/color]

[hermit825]

Yes in fact, I had experimented with a variety of cultivars this year,(outdoors) and under 24 hr daylight, bolting did present a problem, mostly with the loose leaf varieties.
I think that I will start with an 18 hr cycle, and will modify as I experiment.
as far as the mildew factor goes, my intention is to line the office with 8 mil plastic as a vapor barrier and place formica around the walls, problem is in the event moisture does get inside the vapor barrier theres going to be a mess, best I can tell I would be creating an ideal environment for it!

sure do appreciate you reply!

Bill

[gixxerific]

I am starting an indoor operation as well. I am using florescent. I will also be doing the 18 hour cycle while seedlings.

I am going to see if I can find some cool and warm light tomorrow if I have time. For the blue and red spectrum, blue being more important and more close to sunlight. Red is more for making plants taller from what I have been reading tonight.

Good luck

[hermit825]

Yes Flourescent is definately my plan so far, I had recently went to a greenhouse featuring the led's they are really an option since they are so efficient! for my plan I would need 12 of these lights at the discount price of $1200.00 US not including the shipping, heck if I wanted to shell out that much money I would just buy a boat! hehe

I highly reccomend the purchase of

"Gardening indoors with H.I.D. lights" by george f van patten totally superb reading, albiet a little technical.

TTYL
Bill

[gixxerific]

I'm no expert but have heard mixed opinions on the LED's. Mostly saying they aren't up to snuff when compared to other lighting systems.

[gixxerific]

I came across this while doing some research for myself today that should answer your initial question.

You have 403 sq ft total with 16 - 400 watts light you have 6400 total watts.
Smaller plants should have 20 - 30 watts per sq ft. larger plants should have 30 - 40 watts per sq ft. During flowering 40 - 80 watts per.
So at 30 watts per you need = 12090
at 40 watts per you need = 16120
at 80 watts per you need = 32240

So I would have to say you don't have near enough. That is also figuring that the light will be very close to the plants like 4 inches or so. Than again the HO bulbs put out nearly twice as much light as regular fluorescent lights.

Feel free to check me the following is a quote with the info that got me to where we are now. The two links here have a huge wealth of info on indoor lighting. It seems like you know what you are doing but you may want to browse them. I spent several hours reading through all the info.

Good luck, I hope this helps.

What Size Light?
Seedlings and clones, and even small plants in the vegetative stage, will do just fine under 20-30 watts/sq foot. Larger plants in the vegetative stage will do better if given a little more... about 30-40 watts/sq foot. Plants in the flowering stage require a lot more light, and should be given 40-80 watts of light per square foot. Again, these are general guidelines that should work well for plants that enjoy lots of light. It is always a good idea to know the lighting requirements of the particular plants you are growing.

The first step in choosing the size of light you will need is to measure the floor space of your garden area (example: 2 feet by 4 feet= 8 sq feet). Next, multiply this by the watts per square foot you would like (example: 8 sq feet times 50 watts/sq foot= 400 watts). Break out your calculator if you need to, this is important to your indoor gardening success!

In the example above, you would need 400 watts of light to put a 2x4 foot garden at 50 watts/sq foot. As luck would have it, a 400 watt light is one of the standard sizes. The standard grow light sizes are...

https://www.jasons-indoor-guide-to-organic-and-hydroponics-gardening.com/garden-grow-lights.html
https://www.homeharvest.com/whichgrowlightisrightforme.htm

[rainbowgardener]

I came across this while doing some research for myself today that should answer your initial question.

You have 403 sq ft total with 16 - 400 watts light you have 6400 total watts.
Smaller plants should have 20 - 30 watts per sq ft. larger plants should have 30 - 40 watts per sq ft. During flowering 40 - 80 watts per.
So at 30 watts per you have = 12090 (RBG might be clearer to say for 30 watts/sq ft you would need 12,090 to cover the 403 sq feet)
at 40 watts per you have = 16120
at 80 watts per you have = 32240

So I would have to say you have enough. That is also figuring that the light will be very close to the plants like 4 inches or so. Than again the HO bulbs put out nearly twice as much light as regular fluorescent lights.

......
In the example above, you would need 400 watts of light to put a 2x4 foot garden at 50 watts/sq foot. As luck would have it, a 400 watt light is one of the standard sizes. The standard grow light sizes are...

https://www.jasons-indoor-guide-to-organic-and-hydroponics-gardening.com/garden-grow-lights.html
https://www.homeharvest.com/whichgrowlightisrightforme.htm[/quote]

Gixx this is great research and a very helpful statistic to know, but I'm not quite following your math.

So 30 watts per square foot is the minimum you need. OP has 400 square feet, so needs a minimum of 12,000 watts. So how can you say that 6,400 is enough? I guess if you are adding in to that that the HO counts double and the statistic you gave was for regular, not HO, then the OP has just enough to meet the minimum.....

[hermit825]

Both of those links are great! I was planning on just recirculating the air, but maybe I should exhaust... hmm and the dilema's continue!
This is exactly why I enjoy hydroponics and gardening in general, with so many variables involved, I find it hard not to be totally facinated with this hobby! who could possible find it boring!
needless to say I must have spent two hours touring Jason's hydroponic site!

as far as lighting goes, I knew I would be putting a dent in the budget but I know its one of my most important variables!
thanks for the post

[a0c8c]

Always vent the air, and never recirculate. You'll end up with stale air. I had a friend who grew some plants hydroponically in a small room and didn't vent the air, be reciculated it and after a while the air smelled stale. Plants didn't enjoy it either. Ventin the air and bringing in fresh air will definately help out the plants

[gixxerific]

Opps sorry

Good catch Apple.[ed - it was me RBG] It was almost midnight I was tired, I must have been thinking backwards, I fixed my post (I think ). The statistic is for regular. He has 403 sq ft. Not that 3 sq is that big of a deal

Now I have no idea if the double output correlates to wattage needed. It just say's double the output, that could be taken a few different ways. You would have to check in to that. If they actually put out twice the light of regular bulbs at the same wattage you would be okay at the minimum light level. It's also said they put out "almost" double the output. My brain hurts now. You would have to figure in the lumen's as well I believe it only gets worse.

But I was right about those sites. I spent a couple of hours on Jason's as well. Loads of info there. Not just on lighting. Did you see the [url=https://www.jasons-indoor-guide-to-organic-and-hydroponics-gardening.com/plant-life-cycle.html]Plant Life Cycle[/url] section it explained the proper thing to do at each stage of the game.

and Your very welcome. I hope I"m not steering you wrong, you should call wherever you plan to get your light from and tell tell them what you have, I'm sure they will be more than happy to help.

[hermit825]

Yes, I was trying to find an alternative to venting, as in zone 1 my climate often has temperatures that the warmest it gets for the whole month is
-60 F below zero!!

Bill

[JONA878]

Yes, I was trying to find an alternative to venting, as in zone 1 my climate often has temperatures that the warmest it gets for the whole month is
-60 F below zero!!

Bill

And your trying to grow LETTUCE?
Chillie peppers ....radish.....that I could understand....but salad....I ask you.!!!gg

Jona

[hermit825]

am man's got to have a challenge!

[Hydrogardener]

I have been growing lettuce and other greens indoors all winter for a number of years.

The new LEDs work great and are inexpensive to operate. The lettuce in the photo has been growing in this system for ONLY TWO weeks. It is tender, tasty and costs pennies per head to produce.

[img]https://i404.photobucket.com/albums/pp121/hydrogardener/1104.jpg[/img]

My blog has several posts on different methods of hydroponic gardening. I garden 365 days a year, hydroponically.

[hermit825]

the photo, (and your blog) are certainly great incentive to go with LED's and I have to admit there is something about having a room full of such beautiful greens that is truly rewarding, as I am sure you agree!

thanks for the post, I have recently ordered an NFT system, and look forward to posting some photo's soon, but for now I gotta run and cancel my order of t5 flourescents b4 its too late!

Bill

[Hydrogardener]

I also have a large T5 unit and just paid $19 for a single tube. Even the compact fluorescent tubes run $65 each. And, they last a year. The LED will cover 9 square feet at almost 4,000 foot candles and lasts ten years, and uses much less electricity. It is a no brainer. I have not tried tomatoes or cucumbers yet, but I expect no problem when I do.

[gixxerific]

Two weeks Hydro! What am I doing wrong. I put some seedlings in maybe 3 weeks ago in potting soil with fluorescents and they are still puny. I even got 2 red and 2 blue spectrum lights in there.

By the way nice blog Hydrogardener.

[Hydrogardener]

I have been gardening for forty plus years, and in all honesty if my only choice was to garden in soil rather then hydroponically, I would not be bothered. I hope that statement does not elicit an outpouring of outrage from soil gardeners.

[JasonsIndoorGuide]

Hello everyone......I just stumbled upon this forum....

Hermit- if you cannot exhaust due to your local temps, one solution would be to recirculate the air with a much larger body of air (such as the rest of the air in your home). Eventually, the air will still be depleted of CO2 if your home is of a very air-tight construction. Your other option would be to add CO2- not exactly cost effective for growing lettuce but it would allow you to recirculate the air forever without exhausting.

You will likely need to run a de-humidifier if recirculating the air, as the humidity will creep up until conditions are right for mold.

With lettuce, I would not worry too much about a "fungal infection"..... the crop grows to completion too quickly for fungus to get established under normal conditions. If you have had a problem with fungus in the system or in the grow room previous to growing your crop, that is another story (the setup will be predisposed to fungal problems unless you clean everything very well with 5% bleach solution).

Because it is a crop produced in the vegetative stage, lettuce requires less light and less nutrients to produce. Half strength nutrient solution is good for lettuce, and it should do well under 25-30 watts/sq.ft..

Going the hydroponic route does not necessarily mean you must use chemical fertilizers. One product called Canna Bio is 100% organic, made with NO animal products, and is made just for hydroponics. It is also a "one part" hydroponic nutrient, making it easy to mix up and use. It also mixes up at just the right pH, which makes it easy to maintain your nutrient reservoir.

ps.- Thanks for the great forum here! Keep our community growing!

[hermit825]

I have been monitoring my Humidity, and in the arctic its much like the desert, I had been concerned about the humidity levels, and have not exceeded 13% RH in the last three crop rotations, and the fluorescent HO T5's have been working just fine, initially I had problems with my seedlings bolting, but a full spectrum L.E.D. (40w) has solved the problem.

I am tired of mixing nutrients, so I will certainly be looking into the organic that you mentioned!

Many thanks!

Bill

[Ozark Lady]

I hope that I am not taking a bad detour here. But, something posted earlier just caught my eye, and my imagination.

I don't know how to quote so here is a copy of it:
Yes, hydroponics are very finicky. If you get a fungal infection your entire crop will be lost. Also, you be stuck with using chemical fertilizers for the system which add very little flavour to the vegetables (in this case lettuce.)

A better bet would be to set up some shelves with grow lights and buy some potting soil and if they have it some compost as well as some manure and grow your plants indoors with the grow lights in pots. A lot cheaper,and not nearly as much hassle, and a tonne more flavour.

I read that, and then I re-read it. Can someone elaborate on this?
It is mind boggling.... the plants get the taste from the growing medium?

I have never used commercial plant foods nor fertilizers, except on my African Violets, and I didn't taste them... although I hear they are edible.

I am planning on seed starting using aquaponics, the fish will provide the plant foods. But, I can't grow lettuce in the heat of summer, which is when I mostly want to eat lettuce... so I thought about growing lettuce inside under the a/c with my aquaponics.

But, this taste difference, has really rocked my world. How would they taste different? Isn't the flavor set by photosynthesis and the plants own internal systems? I don't use commercial plant foods, because so much natural is available to me, with the livestock that I have, and leaves available. But, I didn't know there was a difference in flavor!

[hermit825]

I had previously read that as well, and read somewhere about switching to a modified solution just before harvest, I am curious about it, but hydroponically I cant taste any difference from what I grow outside in my garden and fertilize mostly with fish fertilizer.

I imagine extremely discerning palate's may notice a difference, but I certainly cannot.


Best of luck!

Bill

[serial_killer]

If it really bothers you, or you planned to sell your crop you can run just water, or buy a solution, two I know of are Botnicare's Clear-X and GH's FloreKlean, that will remove any build-up's of anything that would cause the taste. I don't notice anything, nor do anyone thats tried mine. Its only the really picky people that like to junk on your day and try to say soil is better cause of this or that...
[img]https://i452.photobucket.com/albums/qq247/1badv8dime/DSCN1302.jpg[/img]

[Ozark Lady]

Okay, so it is like facial muscles, not everyone has the same ones! So to some folks it will taste different. Oh I hope I am not one of those folks, I still hate food cooked in a crock pot and I can taste the difference... oh no.

I was amazed at the amount of light suggested. Is that much light required even to start seedlings, or just for maturing plants?

I have done little inside growing... hence the dead houseplants to prove it.. Seedlings are as far as I go, and I am not particularly successful with them, that is why I was going to try aquaponics.

I don't overwater, I underwater... they get crispy and I wonder why, the soil is usually rock hard... forgot to water them again!

[serial_killer]

I just started my own aquaponics experiment! I'm trying basil,which I hear will be a little harder than lettuce, plus I'm using Opal Basil on top of that (even slower to grow and needs more P that green.) Its hard to get pond fish around here this time of year, I had to go with big gold fish.

I also have some extra lettuce seedlings in case it fails, I can stick some of that in there. I have ButterCrunch started to replace what I just cut from my F&D table.

[Hydrogardener]

Whoever wrote this does not have a clue:
"A better bet would be to set up some shelves with grow lights and buy some potting soil and if they have it some compost as well as some manure and grow your plants indoors with the grow lights in pots. A lot cheaper,and not nearly as much hassle, and a tonne more flavour."

If you follow this advice you will be inviting all kinds of pests into your house, and indoor garden.

CNN a few months back listed the ten most dangerous items in today's diet, and at the very top of the list was salad greens. I know this for a fact as my wife and I became very very sick a few years ago after consuming bagged spring mix salad greens. Never again!

Naturally, agri-business interests jumped right to defense mode when the posting appeared on CNN. However, with modern transportation you really have no idea of where, or how, your greens were grown!

I have been growing my own greens for several years. The greens have never had any insecticides, or fecal matter applied to them, and are so clean they do not have to be washed prior to use.

There is more than a pound of lettuce in the photo attached, and it is consumed within a few days of harvest. I estimate it costs me about twenty five cents to produce a head of lettuce, and here in upstate New York, in February, lettuce is going for two dollars a head.

[img]https://i404.photobucket.com/albums/pp121/hydrogardener/lettuce.jpg[/img]