plant lighting?

[catfishfan]

Ive been trying to find adequate lighting for my 30 g planted tank. I guess I need about 100w give or take?? My hood is flourescent and single bulbed. would I have to buy a double bulbed hood or do they make single bulbs with enough wattage? Also, everytime I add either CO2 or plant fertilizer, all my fish are gasping at the top for air. I thought about adding an air stone or bubble curtain, but that wouldnt help the plants. Any ideas?

 

[Nospherith]

Power Compact Fluorecent lights will give you the wattage you need, which is around 3 wpg. People also say avoid "actnic" bulbs (those are for marine aquariums), and a good light for plants would be somewhere around 6700k (kelvin) light which is a natural noontime daylight rating. But then again you could maybe have something like 4 or 5 of those bulbs that you have now set up in a hood assembly.

AH Supply if your the DIY kindof person.

Big Al's is a good online store. Maybe this link might give you an idea of what you need.

-- edit: I just read from ADG, a fairly reliable source, that if one were to choose just one bulb for their plant tank, then 8,000k would be the optimal kelvin rating; however, I think it is suggested that numerous bulbs with different K ratings are better than just one K rating. --

 

[RamJet]

I am looking a doing a plant tank, and was wondering why actnic would not work, all my marine macros do very well under them.

 

[Yenko]

Yes, a good variety of temperatures is a good thing. I'm designing a hood with either 80 or 100 watts of light; that way I can have 4-5 bulbs of my choice. It's also a good idea to look at the diagram that shows what colors the light produced is rich in. Even though I have a light that is supposedly blue, it has a lot of yellow and red in it which make oarnge, yellow and red fish look spectacular. Also, Diana Walstad mentioned research where green/yellow light was ideal for terrestrial plants.

My dad recalls a post on a newsgroup discussing the book. One person said he had a whole room of terrestrial plants (His parole officer forbids him to say what kind ) growing under cool white light, something Diana Walstad reccomends.

The cool white/yellow-green combo simulates the kind of light plants actually recieve in the wild, but for high-light plants that live very near the surface something closer to sunlight may be ideal.

Takashi Amano uses 6800K lights.

Actinic lights provide a simulation of sunlight as it's recieved underwater. I've been SCUBA diving in the tropics, and the lighting 30-60 feet underwater is nearly identical to what you see in an actinic-lit tank. Tropical ocean water is also very clear, so the sunlight is filtered differently than in the usually tannic water most tropical freshwater fish and plants are from.

 

[RamJet]

I too am a suba diver of 19 years now, but what reading I have done on the subject of atinic lighting and fresh water just states that it is of no benifit to fresh water plants. I did however find one artical that stated that because atinic is from the blue spectum, fresh water plants would not use it in the way salt water plants would. I guess I was trying to find out why. If you notic wile diving light disapates and things begin to turn gray at 30 feet. Corals and salt water plants for the most part grow above the 30 foot mark.(With excetions) Now in that same region if you go to fresh water you will find that most plant life is in that same 30 feet and after that it also goes gray. From the reading I have done, it has not been the case of how the water filters the light, but how the plant uses the light. So you have the same light penatration, just a diffence in the plants themselves?

 

[Nospherith]

I think that it just doesn't emit the right spectrum for freshwater plants. Basically, just look at the bulb, it's blue. I'm no botanist, but I can guess that the plant may indeed use some of the light that actnic emits, it's just that it would need more light from the spectrum to thrive. -- Don't marine tanks use non-actnic bulbs? Saltwater plants don't grow well with just actnic bulbs, right?

 

[RamJet]

In marine we need to have atinic to simulate light at around 12 to 30 feet deep. Marine power compacts will come with one Fluorecent and one Atinic for a 50/50 mix of light. This simulates noon time sun. Also, I want to clear up that Atinic is not moon light. Moon lighting is achieved by a simple blue LED light. Atinic is much stronger and not something you want to leave on all night.

 

[steelhealr]

Hi...remember some basic physics. The first light filtered out by water are the oranges and reds. Hence, for us scuba divers, the deeper we go, the darker and bluer objects appear. The most wonderful scuba diving can be in under 30 feet of water because of the beautiful colors. Marine plants growing at 30 feet would use more blue light, hence, actinic's use in marine aquariums. Frank

 

[RamJet]

You must like the color blue, but after 30 feet blue begins to filter out also. This is why we carry dive lights with us in the day as well as on night dives. All the color is 30 feet and above. However, I do agree that there are many wonders happening below 30 feet as well, just not as many colors if you dont have your lights on.

 

[Jen]

I have been told that a 6500k bulb emith the colour temperature that is simelar to daylight, so your plants will like that. I am putting 2 of those bulbs on my 35 galon next week. They are 30 watts each, thats not a ton of light, but the plants will grow.

 

[Silly me]

Hi Ramjet

its all to do with the way water filters light.. in the sea corals and plants grow at specific levels.. meaning since there is only blue light left at 25feet you wouldn't find a blue plant.. as it would reflect the only available light, fresh water plant rarely grows deeper that 10feet (also with some exceptions) so much more red and green are available at that levels.

Color also cause different behaviors in plants. blue light might stimulate the plant to grow faster to reach for the surface, and more red light might cause the plant to think its at the surface causing it to grow more bushy