What's your Lightings intensity

[naturetan]

60X30X35cm
PL 36W
~2W/gal

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On 11/26/2003 5:09:15 PM

I am contemplating of added 2 X 18 watt fl tube to my current 36 watt. This will make it to approx 4 watt per us gallon. Also afraid Algae out break.

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Used to run my tank with 2XPL light, ~4.5W/gal or more for PL. Maintainance is tough, and plants grow too fast. Also a waste of electricity.

[bettapassion]

Hi,

Would it be helpful if members could also indicate the temperature K?

[sherchoo]

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On 11/27/2003 9:04:11 AM

Hi,

Would it be helpful if members could also indicate the temperature K?
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Noormally, lighting temperature used is usually 6500K.... at least mine is.

[hwchoy]

dun know, the normal daylight PL tubes [:0]

[bettapassion]

Does increasing the K will give red plants better chance? Cause I find that my red plants not doing well unless the grew tall enough to reach the light then I see better leave growth and color.

[joe]

1.5 x 1 x 1ft tank
36W + 55W (91W total)
9W/gallon

[murphys33]

yep... my APP bubbles only when the 55w light turned on... otherwise with only 72 w(ie 2X36w)lihgts only, they dun bubble

Temp wise, never exceeds 28degrees... range 26 to 28...
in any case, my tank is about 20 inch in height

[hwchoy]

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On 11/27/2003 1:50:31 PM

yep... my APP bubbles only when the 55w light turned on... otherwise with only 72 w(ie 2X36w)lihgts only, they dun bubble

Temp wise, never exceeds 28degrees... range 26 to 28...
in any case, my tank is about 20 inch in height
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anyway they don't have to bubble to do well. bubbling simply means that so much O2 is generated that it cannot dissolve into the water fast enough.

[jellydot72]

Hi Joe,

Hey....9 watt per gallon![:0] I guess I'll wear a sunglass to look at your tank man, heh heh heh.... [] I suppose the water temp. is high?

jellyman

[joe]

jellydot, actually no ... temp is 24-26 ... in office mah [:]

[jellydot72]

Hi Joe,

No bad har....got centralised aircon hor.... []

i have a 20cm cube tank that i with 7 watts per gallon and have to place a fan on the filter to bring the temp, down to 24 - 26 if without it can climb to 33![:0] Alternatively I should try to bring it to my office.... arr...must hide from my boss...heh heh heh...dunno he mind or not.

Jellyman

[naturetan]

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On 11/27/2003 9:34:17 AM

Does increasing the K will give red plants better chance? Cause I find that my red plants not doing well unless the grew tall enough to reach the light then I see better leave growth and color.

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I've tried both 6500K & 10000K on my red plant like Macrandra, no difference I could observe from either light.

[PohSan]

Lot of the AQ members got more than 4w / gallon !! I thought around 3w/g will be sufficient even for high light demand plant?

Regards,

[jellydot72]

Agree with you....that was also in my mind 3 watts. i have just add more tubes. Now at 4 watts. And I am watching out for algae!!! heh heh heh[]

jellyman

[PeterGwee]

More light generally means more work on the nutrients and a close eye on CO2. Run low on either of them and you get trouble... Want red plants to grow more red..drop the NO3 lower than 5ppm should redden most red plants up. Just be careful on the lower ranges...you need very good test kits for this but an experience eye would also do..

Regards
Peter Gwee

[naturetan]

Not sure what light demanding plants you're refering to. I've tried several light-loving stem plants, only 2Wpg, without any problem. Yet to find any that will fail under such lighting.

IMO, around 2-2.5Wpg is more than enough for most plants.

[murphys33]

Hi guys,
Do refer to this link:
http://www.thekrib.com/Plants/Tech/Lighting/

It argues that intensity is better measured as watts per surface area.... under the description, mine falls into medium light category and not hight light that may be assumed as i have >4w/gallon

[hwchoy]

It makes every bit of sense, for tank no more than 2-2.5ft deep anyway. It is good to see some dataset support for the idea. In this measure, my time (3.85W/gal) rates only as a high-medium or low-high tank

[vinz]

Actually, some of the ppl in the APD have already confirmed recently via experience that larger tanks do not need 3WPG. The 3WPG guideline does not scale properly with tank sizes.

I used to run 432W (12x36W) on my 171USG (6'x2'x2') tank, some 2.5WPG by tank capacity and close to 3WPG by actual water volume (143USG). When I dropped it to 324W (9x36W), the plants hardly responded to the change.

Conversely, some ppl have found they need to pile on more then 3WPG to get riccia to pearl in a small tank.

Something I wrote in another thread recently:

"So far this is the experience of some of the large tank owners. Personally, my plants hardly seem affected when I reduced the lights on my 6 foot tank from 2.5WPG to 2WPG (by tank capacity, not actual water volume).

Maybe I can illustrate why. Say you have a typical 2 feet tank which is about 20 gallons. At 3WPG you need 60W... which for practicality, translates to 2x36W PL over the tank - more then 3WPG. Now consider a 2ft cube, 54 gallon tank. 165W is needed which is roughly 5x36W.

In the typical 2 ft tank, the plants have only 2x36W light above it. The 2ft cube tank has 5! From this you can see that the 3WPG guideline is not really "scalable".

Ppl will argue that there is a difference in height. I will not disagree, but I don't think you need 3 more PLs just to punch through the 8 or so inches height differences. Probably just one more would do. So the 2ft cube will have 108W which works out to just 2WPG."

[Aquabeanz]

im using 216W, underpinned by 6 PL tubes for my 190litres.
i personally find that its more difficult to fine tune the co2 and fert dosages, probably because of the faster and higher intake of these essentials by the plants...
am i right? not really sure..