Hibiscus Lighting

[Jordan]

I was sent a catalog from Zoo Med today. As I was flipping through I found that they sold some lighting that I was really not aware of. They where in the aquarium supplies but I found that one looked very interesting for the delima of keeping a hibiscus healthy. Information that I have found on the internet said that they needed concentrated light at 6500K. This lighting was a full spectrum flourescent bulb that peaked in the 6500K range. Perhaps I may have miss read something along the way or miss understood what I was reading. This to me looks like a good addition for anyone that has or wants a Hibiscus in their chameleon enclousure. I figured if I was wrong about my information that someone would correct me. The name it is sold under is "Ultra Sun".

 

[Will Hayward]

Florescent bulbs that are specific towards providing the spectrum that affects plant growth can be bough for extremely cheap at local stores like Home Hardware.

UVA (380-315 nm) - UVB (315-280 nm) - UVC (280-10 nm)

UVC is deadly. It causes cancer (as can UVB) and is used in industrial sterilizing techniques. UVA definetly isn't completely safe either but each have their benefits and drawbacks. Luckily, 99% of UV that passes through the atmosphere is UVA.

Plants don't actually need all too much UV light... and UVB can be harmful to plants, but odly enough its wanted for reptiles that we keep on them! In indoor crophouses where plants are grown and farmed without contact to the sun, The lights that are used are always covered with glass, as to block the UVC and all UVB.

Red (660 nm) and Infra Red (730 nm) can determin how plants grow. More IR than Red light will make plants tall but lanky. More Red than IR light will make plants stumpy and thick. Different plants can respond differently.

Thats how I understand it. You'll notice that different bulbs have different glowing colours, some of them are caused by the spectrum that they focus on. Plant bulbs are often blue (good for plants) or red. If that isn't enough to confuse someone, I don't know what is.

 

[Jordan]

It said that the light was IR certified. I was not sure what that meant until you posted that. I was a little unclear as to what the 6500K actually meant. I found several sights that made reference to this in hibiscus flowering and then saw this light. I suspected that leaving the light off for part of the year could provide the plant with some down time. Then turning it back on. I figured this would provide a seasonal change. I will keep searching. Some one else has got to be interest so I am sure we can get to the bottom of this. It is confusing.

 

[Zerah Morris]

6500K is simply a reference for full spectrum daylight bulbs. The K refers to degrees Kelvin and is measured by heating black steel. Once heated to 6500 degrees Kelvin the blank of steel glows the same color as the light produced by these bulbs, more accurately the bulbs produce light the same color as the steel glows. In reef aquaria the Iwasaki line of Metal Halide bulbs were some of the first used to successfully keep photosynthetic coral, they emit full spectrum light in the 6500K color temp (yellowish white). Many reef enthusiast still swear by these bulbs because of their high PAR value and intensity. The problem was bulbs in the 6500K range emit a spike of intensity in the red spectrum as your graph demonstrates, this result in alarming growth of undesirable algae. Green plants thrive under this type of lighting. However to more accurately represent the light available to coral on the reef, and to slow the growth of green algae, a shift was made to color temp bulbs more pleasing to the eye, most notably in the 10000K (pure white) to 20000k (bluish white) range. The PAR value and intensity of these bulbs is not as high but the color temp provides enough actinic light to cause the coral to "glow", and the bulb still provides the necessary radiation for photosynthesis to tanks 24" deep or less if high enough wattage's are used.

As Will mentioned fluorescent bulbs in the 6500K color temp can be purchased anywhere as "plant bulbs" or full spectrum daylight (5500K-6500K). The problem with hibiscus has more to do with intensity than color temp however. As light moves through the air the falloff in intensity is huge, as we have noted in this hobby by our study of the penetration of UVB. The Inverse Square Law-Being a point source of light, as you get closer to a MH bulb the intensity increases at a rate of the square of the distance. If you really want to grow hibiscus you need to look into high intensity discharge lighting sources that are point source, i.e. MH, MV, Halogen. Running a 400-watt Iwasaki lamp in an unshielded enclosure would grow plants like crazy but would blind you and your cham. As a result most MH bulbs are run with a shield of glass over the fixture, and if you choose the lamp in a mogul socket base it also has a envelope of glass around the actual bulb. Now if you run double ended MH bulbs there is no extra envelope of glass and you MUST shield the bulb with glass. Even with the glass shield the bulbs still produce a considerable amount of UV radiation in all three spectrums. The problem with these bulbs is and always will be heat, but it can be controlled.

While not condoning the practice most closet systems set up to grow marijuana are based around the Iwasaki 6500K mogul based MH bulb. It's PAR value is unequalled and its light penetration is unmatched. As a result it produces the most radiation available for photosynthesis.

Now that the water is really muddy...

 

[ClmbrJ]

well Zerah since you brought it up......

I have a friend who uses the "high photosynthesis" set-up and I have asked him a lot of questions about it and toyed around in the grow room with thermometers and humidity guages. From what few experiments I have done it looks like I would need a seperate a/c system for my cham to run those lights in MY ENCLOSURE. now, there are a lot of reasons for this, but surfice it to say it seems the heat to light ratio is off. Basically, to get the temps where they need to be, the light would either need a high speed fan, or would be out of range to be effective in lighting.

THEESE THINGS RUN HOT!!! now, on the other hand he runs four bulbs in a 10x10 room and WOW!!

my set-up is in a small bathroom, so even one of these bulbs best I can figgure would mean the minimum temp would be at least 85f.....too hot

Perhaps in a larger room I could see where these things would be fab! but, My friend has a secondary fan drawing 950 cfm off of a 800sf room, with a window mounted a/c on top of the central air running almost constantly and his four bulbs still have the room at almost 87 degrees whenever they are on.

All this equates to a bigger electricity buill for not much gain if you ask me.
I have hybiscus in my enclosure, I just had to add a second reptimed...much easier and does the job just fine without the bills.

 

[Zerah Morris]

but surfice it to say it seems the heat to light ratio is off.

THEESE THINGS RUN HOT!!! now, on the other hand he runs four bulbs in a 10x10 room and WOW!!

All this equates to a bigger electricity buill for not much gain if you ask me.
I have hybiscus in my enclosure, I just had to add a second reptimed...much easier and does the job just fine without the bills.

All of these statements are common misconceptions of MH lighting regardless of the intended use. Think of it this way. How many 100-watt bulbs would it take to equal the light intensity, PAR, and penetration of a single 1000watt MH? If possible, we are talking hundreds of bulbs. The heat generated by these bulbs, and the power draw would be far greater than that of the MH bulb. Even is we look at fluorescents and compact fluorescents they still produce considerably more heat per watt than the MH, the difference is it is spread out over the large surface area of such a bulb. CF is often touted as a replacement for MH in reef aquaria. They are marketed as cooler running. Bogus, if you took 1000watts of compact fluorescent and squeezed it into the same physical size as the MH (about 1.5"x1" remember the large bulb is the envelope not the bulb) it would be tremendously hotter and still produces lower PAR values and less intensity/penetration.

The key to effectively running MH is isolation. I have never grown plants indoors with MH but if I did I would mount my reflector and housing in the ceiling cavity and have the lens come into the room, similar to a can light. Now you could simply vent the attic with a large exhaust fan, step up to R30 batting and keep the bulk of the heat out of the room while still enjoying the benefit of the light.

While The Inverse Square Law does demand that the light fall off considerably as we move away from the bulb, the penetration/intensity is still such that the plants on the floor 8' from the bulb will still have near natural PAR exposure if you use an efficient reflector and quality ballast to fire the bulb. Futhur the use of remote electronic ballast will significantly reduce the amp draw needed to fire and run the bulbs, and produce less heat as opposed to the tar ballast typically used by growers.

 

[Jordan]

I guess I am kind of curious what effects lighting like the flourescent bulb might have on the overall color brightness of the chameleon. I have seen a couple chameleons kept under M.H. lighting that looked very bright. I guess for me they just seem like to much for the type of enclousures I am willing to keep them in.

 

[Fate X]

i would get a 150 watt sun agro mini hd system for one of my chameleons after i find the right bulb which i think might be a sun agro

 

[rcagosto]

Zoomed sells a somekind of plant bulb, forgot what it was but they do. I was actually thinking of getting one, but I also have to worry about the electricity bill.