I'm not familiar with that particular lamp, but this thread will explain most of the considerations involved in determining how specifically useful a particular lamp is for plant growth.

Here is a link that might be useful: For reference: Footcandle measurements for a two-bulb T8 fixture

Thanks, OrchidsNYC. I did go through many, many posts yesterday with respect to the basics. I just wondered if anyone out there has tried these bulbs specifically?

Hi Amy! I'm so glad you want the skinny because I don't want to get started on another thread. I would never buy these tubes. I've looked at the wavelengths they emit on a graph and thought, "Oh me, oh my. Another sales gimmick".

I appreciate your concern, Amy.

John, where have you found SPDs for Philips lamps? They said they would fax me ones for specific lamps when asked, but as far as I could tell there are none at all anywhere on their site. Did you find them elsewhere?

I have info on the GE Plant & Aquarium tube, could you possibly be referring to this?

No, I thought you said you'd seen the SPD for the Philips lamp "Assertagirl" asked about and I was wondering where you'd found it.

I asked my wife to pick me up a couple of gro tubes while she was in town and she came home with a couple of these Phillips Plant and Aquarium bulbs. The packaging claims 2700 degrees kelvin. I can't see where they would do any good for plants or aquariums.

What makes you think 2700K is no good for a plant light? Don't fall into the whole macho metal halide pot-grower more is better thing on the colour temperature. The colour temperature is a silly spec to give for this type of lamp anyway, its maningless. Just like the CRI.

FWIW, 2700K is the colour temperature of the theoretical ideal mix of red and blue light that these plant fluorescents are aiming for. The enhanced HPS lamps also have a CCT near 2700K, although again it is a foolish number to use for a lamp with such a spiky spectrum.

I don't have any specs for this lamp either. Its probably just like the GE one, and therefore similar to a Gro Lux. Can anyone who has one describe the colour of it? Pink? Purple? White with a hint of?

I bought the Philips P&A tubes as backup for when my other fixtures/tubes died or needed to be replaced since that's all they had at HD at the time. I've used them at least twice so far for about 2 months or so. Had no problem growing plants (flowering plants and micro tomatoes) with these bulbs. In fact, my tomatoes started flowering early under them. These tubes have a slightly purplish cast (red and blue spectrum). They are fine for plants.

When I first got them, I contacted Philips to ask about them and they confirmed that they ARE grow lights for plants. They sent me a pamphlet on their grow lights, but it was mostly for their Agro-Lite bulbs. It also included some useful info on growing plants under lights (photoperiod, temps, fertilizing, soil, pH, etc.).

Shrubs, I guess it's a throw back from my aquariums. I grew up with fresh water tanks and continued them when I got married. We switched to reef tanks about 18 years ago. Now we have decided to try indoor gardening along with the reef tanks. Help keep the electric company in business. lol. Anyway, I had an extra Ice Cap 660 electronic FL ballast and an old GE 4 bulb fixture with a fried ballast. Put the 2 together, added 2 New Sylvania F40/CWP/CVP bulbs and 2 old Gro-Lux Aquarium bulbs. The Sylvania's are 4100K which I figured covered the red end of the spectrum and the Gro-Lux (which to me appear white/UV) to cover the blue end, sort of like I do on our 2 mini-reefs. I use 6500k and 7100k power compacts. 7100k are Actinic Blue bulbs. The red end of the spectrum doesn't do much for reef tanks, which I new that land based plants need, thus the 4100k. I have 3 250w 10000k bulbs on my 120 and 3 400w 10000k bulbs on my 180 and they are quite blue. We brought 2 cacti in from outdoors and started 2 banana peppers and 2 jalapeno peppers. Everything is growing, but the Gro-Lux were pretty old and I figure the spectrum is probably way off from new, so I had the wife pick up a couple new gro bulbs to replace them. All she could find were the Phillips bulbs (which are pink by the way) at 2700k. Now in the reef tank world the higher the kelvin the bluer the light for the most part, so I figured 2700k isn't even close. Not sure what the kelvin is on the old Gro-Lux. They are over 18 years old from my fresh water days. Wife says I never throw anything away. She may be right.

Dana

Happy to hear these bulbs work. Now I won't have to take them back.

Frank

Reef tanks need a lot of blue light, and even UV, so generally you need a very high colour temperature. Surface plants don't, they need a lot of red light and also some blue light although they are happy enough with any range of wavelengths that includes some red and some blue. A regular "white" 2700K warm white fluorescent emits a lot of red light, some green light, and very little blue. Its useless for a reef tank and not even great for plants unless you add some more blue. Add in a 4100K or 6500K lamp (which have a fairly even mix of red, green, and blue) and you have a decent light for growing plants.

The 2700K (-ish) Gro-Lux and Plant&Aquarium lamps are different, they are a mix of a lot of red and some blue, nothing else (not much else anyway). It still averages out to 2700K but it is fine for growing plants because now it has both the red and the blue. It will even add something to a reef tank because of the blue light but I guess the red is a bit of a waste (don't some algae like the red though?). CCT (the 2700K number) is a very poor way to represent what these lamps do and they probably shouldn't even stick it on the spec sheet. Colour temperature is only really meaningful for light sources that bear some resemblance to a continuous black body spectrum like an incandescent light, or at least a spiky spectrum with a spread of spikes to produce a pseudo-white light for humans.

Shrubs,

Thanks much for the clarification. So my 2700k and 4100k is a decent combination. One of my cactus that was given to me in the spring spent the whole summer outdoors and didn't grow at all, but under these lights on 18 hours a day, they have grown quite a bit in the last 6 weeks(and that's with the old Gro-Lux).

You are right about some algae liking the red spectrum, but it's mostly nuisance algaes that smother out your corals and cover your glass.

Thanks again for your time and info.

Frank

I have used the Phillips P&A bulbs for both growing aquatic plants at a depth of 24 inches under hard alkaline water and growing indoor plants along with water surface residing water lettace. And to be honest, they have yet to disappoint me in any way. All the plants no matter which type were growing, under water, on top of water, or in containers with top soil, they all had good growth, nice looking flowers, and a deep green base color to the leaves and stems. Since I have roughly 45 aquariums running at all times in the house I look for inexpensive ways to light them all (all bulbs are replaced at the same time at the end of tax season). All the bulbs I use are replaced every 12 months since the light intesity degrades over time, some sooner than others depending on the amount of time per day they are being ran. This year just as an experiment I am going to try growing tomatos indoors under a Trinitron bulb to see if there is any advantages or disadvantages. As my favorite saying states "lifes an experiment, live and learn."

-Christian

Power compact and VHO whip the t-12 and t-8 lights. T-5 are bright, expensive, and run hot. Hybrid t-6 lights are a better choice. Halide has a deeper penetration after 18" (*in or out of water). Pay more attention to the color temp of bulbs than the CRI. They are all the same Chinese tri phosphor, so don't get too stressed. Mix the colors up and enjoy.

Surprised that nobody has played with the actinics ;)

> Surprised that nobody has played with the actinics ;)

I started a thread, "Why not blue?", because I am thinking of playing with actinics, or at least actinics plus triphosphor (50/50 or 10,000K bulbs).

> Hybrid t-6 lights are a better choice

I only know of two online suppliers of T-6
http://www.naturallighting.com/
http://www.bigalsonline.com/

>They are all the same Chinese tri phosphor, so don't get too stressed

If the Philips Plant & Aquarium is similar to GE's namesake, it would be a "deluxe", not a triphosphor. Some of the T-6 bulbs linked above would be "enhanced triphosphors" (triphosphors plus 1-4 extra phosphors). 420nm or 450nm actinics (pure blues) are not triphosphors.

Pay more attention to the color temp of bulbs than the CRI

If the CRI is markedly different then most likely they aren't "the same chinese triphosphor". The basic triphosphor combination gives a CRI around 80 for a 4100K tube. To get a CRI above 90 you have to use more or different phosphors. Whether this really matters to a plant grower is a whole different question, and CRI alone certainly doesn't give the information you need.

T-5 are bright, expensive, and run hot

T5 tubes are designed to run hot and they work better when hot. This is to your advantage if you are running them in a hot environment such as an enclosed propagator. They don't actually produce any more heat than other tubes (eg. a high output T8), but it is produced over the smaller area of the thin tube and in a smaller fitting. For the same reason, the light intensity of the tube is much higher even when the total lumens are the same.

Halide has a deeper penetration after 18"

This old chestnut again. The "penetration" of a halide is no better (worse in fact) than the "penetration" of fluorescent tubes that produce an equal quantity of light. The advantage of HID bulbs for lighting tall plants and into deep water is that the huge quantity of light is produced from a single bulb that is much more convenient than the equivalent array of multiple fluorescent tubes (and you may not even be able to fit the fluorescents into the available space).

Power compact and VHO whip the t-12 and t-8 lights

Its perhaps also worth mentioning that power compacts are less efficient (lumens per watt, or any other measure you wish to use) than the best T8 tubes. Their niche is where their shape allows you to get a lot of light from a small package without going to HID. That's a smaller niche than most of the marketers would have you believe. If you have room for a 40W (or 54W, or 32W) straight tube then choose those, HO T8 if you have lots of space, T5 for squeezing more light out of a small area.