Backyard Aquaponics
A place to discuss aquaponics

Doug,

I live in South East Queensland - in abut the top third of our continent. Our daylength extends from the shortest day of the year in June (about 11 hours) to the longest in December (about 15 hours). It's got to do with our proximity to the Equator.

Tasmania (an island south of the continental mass) would experience shorter days......but not to the extreme that you guys do.

Because of the pervasive nature of American culture (and particularly its media), we understand American English pretty well......probably better than you do Australian English.

I understand, given the cost of electricity (relative to other energy forms) why your focus is on 'cool' light.

Gary

Gary, I did not know any Australian slang when I started on this forum. And some of the terms on this forum go right over my head.

I do not assume anyone from another country understands my slang. I have gone to Germany on business trips with my colleagues. I was embarrassed by their lack of courtesy, using slang and mumbling . Our hosts in Germany (Daimler) did all conversing in English for our convenience. So I think we owe them the courtesy of speaking clearly in fundamental english. Because of the popularity of music with English lyrics, most young Europeans speak respectable amount of English. Very, very few young Americans speak another language and sometimes very little English

I am going to do some reading about MH at the link from njh. I guess that will be the end of my progress until November when I can run some actual tests.

I need to look at a globe and see where S45 latitude falls. Does the 23 degree tilt of the earth somehow favor number of day light hours in the Southern Hemisphere? Does the North pole always tilt away from the sun? Maybe that is why. It was a long time before I understood why you did not fall off down there

No, I was just saying that MH are _on average_ more efficient than fluoros, but of course there are examples of specific fluoro/MH combinations which are the other way around. However, the most efficient MH is considerably more efficient than the most efficient fluoro.



They claimed 70 lumens per watt, which isn't greatly different from most CFL. Ignore everything else - lumens per watt is your best guide to efficiency. An experiement is of course even better, and if you are willing to do a side by side comparison, that would further the science of AP.



No worries

I just woke up so please be gentle here rofl.........with all this talk of efficiencies.......one might be more efficient but how does it stack up in its comparson to grow a plant as opposed to being efficient at just illuminating it.

I just installed 4 6500K compact flourescents in ceiling cans in my office. Wow! I never knew my wood floors were this color!

tamo42

Would you say they give you the color you would see in full sun light? Or is it different than it would be in sun light?

I think you mean the same as sun light.

I have put up a Fluorex 65 watt barn lite at the peak (~35' AGL). The color temp is 6500K and the light is very white (sun like). What a difference from the HPS that it replaced.

muz / doug,

I get where you're going with the "cold" lights and heat. What i was getting at was that to my knowledge, 150W of fluro will actually generate more heat thatn 150W of MH.

Before you go don't forget that the heat from the fluro's is spread over 4 or more feet length where as in the MH it is in a much higher concentrated area.

Of course i might be completely wrong.

The way that i look at it is;

(ALL ARBITARY FIGURES FOR EXPLAINATION PURP ONLY)

150W fluro 40% efficient (elec. to light)
150W MH 60% efficient (elec. to light)

means that the fluro will generate 60% heat from its input power
means that MH will generate 40% heat from its input power

Like i said % percentages were for illustration only.

Don't forget energy can be neither "created" or "destroyed" and as the light put out negligible RF, sound or mechanical energy, heat and light are the only two conversions.

ergo, if a MH is indeed more efficient (elec to light) than fluro then the fluro MUST generate more heat per electrical W input.

Does anyone else get what i'm saying. If i've stuffed up somewhere along the line please let me know the folly of my ways

Steve

I agree 100% steve. perhaps the cool light thing refers to colour temp?

lol I get ya steve....I sell the bloody things (the company I work for are the largest lighting distibutor in oz....AND NO IM NOT TRYN TO SELL ANYTHING).......AND I DO recommend that doug....or others go look at a website that involves growin marijuanna...there I said it ....these ppl know far much more that US coz THEY have been there and DONE THAT



ahhhhhh that feels alot better....dont try and re invent the wheel...be daring...be norty and go look at a dope growiin website hey

it might.

i've seen a 10,000K (or was it 12,000K) MH for marine aquaria..........very cool light (blue), very hot light

Anyway, main things to remember are;

incadescents = BAD
what ever discharge light you use make sure to change the tube after the rated hours to maintain plant growth (and safety for MH)

Regarding the PAR / lumens thing, i think it was AM or J7au (could have been me ) that compared the purple growlux tubes to a standard tube.

We perceive the growlux as much dimmer than the standard, plant growth tells a differnt story.

LOL BK, i tried suggesting that a little less obviously

I once saw a thread get VERY nasty, and on lighting of all things! LOL

persuit of knowledge takes you to interesting forums indeed!

I use both grolux tubes(pink) and blacklight blue tubes( dark purple) very little visable light emitted from either

tubes are graded in cool white(4000k)......warm white(3000k).....daylight(6000k)....skylight(8000k) then same in triphosphor.....840, 830, 865(6500k) and 880

I mostly use the tubes in my reptile enclosures( for 10yrs) and in my indoor aquarium


sittin here with me catalogues that im brought home from work but cant find lumen specs for the grolux/blacklight tubes..will keep lookin lol.

I know nobody wants to listen to me lol but I still say normal fluros dont cut it ( no matter how bright they are) unless your just wanting to light up ya plants n say here are my plants dont they look good lol...but hey I know jack, but me plants grow better without the normal fluro's and u can prophesise and whack off over figures etc all you like but the SONT-AGRO works best lmao..........and always replace your GROLUX tube after 6 months lol

ps always wash your hands after going to the toilet, always be nice to your mother, dont drink, dont smoke and dont go lookin at dope growin websites coz they might teach you sumthin

does it quote PAR maybe? considering they're for plants?

I agree with the growlux / normal thing.

Thats why ost people have fiztures with one growlux and one normal.
normal so plants look nice, growlux for plant growth

I am glad I started this topic. Learned a lot.
No doubt MH is the current light of choice for plants.

I just looked at my Farmtek catalog (they do greenhouse stuff). I can get a 150watt MH, enclosure, power supply for $99US or a 400 watt MH for $119US. The largest Fluorex is 100 watts and costs $59.99US (they just went up from $50). I will get a 400 watt and do a runoff, but that will not happen until November. BTW, urban legion says, if you order a few MH, then they are delivered by men in black who want to see your greenhouse.

I noticed Steve related Fluor to 4' tubes. Not so the Fluorex (see my post with the carton photo). Question is: are the fluorex anything like standard fluor? If so, story over. To me, the 6500K light is full of blue light and very, very white in appearance (does that mean good PAR? maybe.)

Instead of saying who has the highest efficiency in generating wide spectrum(sun like) light, I will say that whatever light grows the plants satisfactorily for less kilowatts is the light for me.

We have many challenges in the cold, dark North. All of which can be countered by energy use. My challenge is to succeed with the least energy requirement. This with hopes of future operation from sun only.

I already have done the numbers and artificial light is a challenge that is not solved. njh and Janet did some energy calcs and it is a lot of power to get from solar (read $$$$$$ here).

I know Tilapia and other warm water species are the best fish, but not unless I heat my water to 70-80F all year (now there is a lot of energy )
So I choose fish that can live with ice over the water and they grow slower and take two years to grow out.

So when you see me struggling against common knowledge and known best practices, it is probably because I need to meet some energy requirement.

I guess, like Darwin and other heretics, I face criticism or misunderstandings. That is fine. Just keep trying to straighten me out, I learn from your comments.

njh did some calcs showing that the heat exchanger will be useless. Great job on conduction and convection calcs. I have experienced better results in 'real life', so what was the missing factor? I think the major heat transfer mode in effect is radiant energy from direct sunlight. njh did not include this. His model was a heat exchanger working from the temperature of the space around it (working on room heat). That lead to very low numbers. In fact, today is sunny and I can not keep my hand on the flat black tubes of my exchanger. They are directly heated by radiant sun light and therefore are not isolated by stagnent air near the tube surface. The best model for the heat exchanger has radiant energy as the major component. The exchanger will still be a small effect on 3000 gallons, but it will be much more effective than the room heat model. Pardon the techy talk, but it illustrates how discussion benefits everyone envolved. I established the first 'realtime Hardware in loop' simulation facility for powertrain engineering at DaimlerChrysler. I still have a contract to go back and teach simulation 8 weeks a year at DaimlerChrysler. The simulation has vastly improved the efficiency of testing the powertrain controller algorithms. They now have 14 $500K HIL simulators and the engineers are now using simulation throughtout powertrain engineering. I think less problems are getting out to the customer, so I earned my keep.