PL or FL Light good for plants

[fishy_23]

Hi guys,
Is PL or FL better for plants?

[hirowen]

Hi guys,
Is PL or FL better for plants?

It's the color temperature of the lights. Normal PL will have sufficient color temp. For FL, must look for those that reccomended for plant, normal household FL tube will not benefit the plant.

[dc88]

Not true.
PL and FL different in the tube design and light intensity but you can get same color temperature for both type.
FL there are the T8 (normal 'shop light') and the newer T5 (and few other not so common size) T5 is smaller diameter, more compact hence higher intensity than T8. PL is U shape.
Compare normal FL (T with PL, PL can have more wattage & lumen than FL of the same length.
Example, a 18W FL T8 length is about the same as a 36W PL.
For light color (temperature), commercial avilable are 3000K (warm white), 4000K (cool white) and 6500K (Cool Daylight).

In fact I just learnt that Osram has come out 7 color temperature available :
SKYWHITE (8000 K), Cool Daylight (6500 K), Daylight (5000 K), Cool White (4000 K), White (3500 K), Warm White (3000 K) and INTERNA (2700 K)

For planted tank, we normally use 6500K. (hmm, may be should make query on the new Osram 8000K as it is closer to the Amano light series ! May be cheaper....)

PL is getting common nowsaday because of cost coming down and more available. But there are still people use FL for cost reason. For example a 2 ft tank, if you do non-CO2, 2x18W FL is good enough and very cost effective. If you do high CO2, you may need 2x36W PL.

[eddyq]

Personally, I prefer using PL lights as they are cooler in operation (less heat) if used with e-ballast. Also cheap (about $10-12 per tube) and last quite long (about 9 months).

Also, needs to consider the type of plants and the height of the tank.

[Justikanz]

My take on this...

PL - For the same length, they will provide more wattage and thus more lumens. Which is good, as it means more light is being packed into the same package... The bad side is that they are also hotter.

FL - There are at least 3 types of FL light tubes available, T5, T8 and T12. The bigger the number, the thicker is the diameter of the tube. Common ones are T8s. The more expensive ones will be T5s, which comes in NO and HO (normal and high output). I think there is also a low output option... T5HOs are the more expensive ones as they pack more wattage and lumens in a narrower tube = space saving. These tubes are also cooler than PL lights...

But what is more important, when choosing lights for plants are the colour temperature and spectrum. We are a little less restrained by spectrum, though.

The 'right' colour temperature for plants should be between 6000K to 10,000K. However, some people also use 3000K tubes. The smaller the number, the more red and yellow the light will be.

In my opinion, once you are used to seeing 8000-10,000K lights, everything else will look too yellow... So, you guessed it, I am preferring to use 8000-10,000K tubes.

I would also opt for T5HOs if you have the extra cash. The cooler temperature and the brighter lumens sure make up for the initial investments...

My 2 cents...

[PeterGwee]

You do not need high light even if you opt for a CO2 enriched tank. More light equal to more need for nutrients and CO2 and all that means just faster growth and less room for error. You can drive things slower with less light and more room for error if you forget to dose or the CO2 dips a tad.

Regards
Peter Gwee

[Justikanz]

Agree. You just need to provide everything else proportionally more as well if you go with T5HOs... Else, you are inviting algae to get a foothold...

But I will prefer FLs than PLs for heat management...

[FishFan]

Hi,

Can FL operate using E-Ballasts? Iron core Ballasts are hotter than E-Ballasts and I was wondering whether the heat load reduction using T5HOs would be negated by the Iron-core Ballast.

[Anthen]

i using PL light..
PL light is always better than FL liao..

[fishy_23]

thanks guys for the quick reply. Juz one more question, will Pl consume more electricity than FL?

[brianclaw]

It depends on the wattage of the tubes. It's like asking which is heavier, 1kg of bricks, or 1 kg of feathers?

[valice]

It's like asking which is heavier, 1kg of bricks, or 1 kg of feathers?

they are the same?

[juggler]

Hi,

Can FL operate using E-Ballasts? Iron core Ballasts are hotter than E-Ballasts and I was wondering whether the heat load reduction using T5HOs would be negated by the Iron-core Ballast.

eBallast and magnetic ballast can be use interchangeably on PL or FL lighting. If you use eBallast on FL lighting, then no starter needed.

[juggler]

thanks guys for the quick reply. Juz one more question, will Pl consume more electricity than FL?

Should be about the same. Maybe some newer T5 are more efficient?
But if used with eBallast will be more efficient.

[FishFan]

Hi Juggler,

Thanks for your reply. Hope that you can entertain a few more questions.

1. For the same wattage, am I correct to conclude that a light set-up of FL with E Ballast compared to one with PL with E Ballast would generate less heat?

2. For a 4ft planted tank, any ballpark prices for the 2 set-ups and a comparison of their operating costs?

3. What is the expected reduction in temp of FL lights with E Ballast compared to PL with E Ballast? 1 - 2 degrees?

4. Any brands to recommend or LFS to visit? Off hand, I guess that NA would be a good place to start.

Thanks!