Lighting Planted Tanks

[CuckooJay]

I know this is a prety standard question... but I'm looking more for experiance than facts and figures.

I am setting up a 75 gal planted tank. Well, really all I have left to do is build my canopy. I don't want to have any problems keeping whatever plant I feel like. I know fertalizers, CO2, substrate ect. prety well, and I won't be skimping out on these details. Basically I want to do a GOOD job on this thing. So...

What wattage should I be using?

What Kalvin value is best?

How do I compare these factors to the height of the tank in order to get a better value than "watts per gallon"?

If my lighting is "intense" for more demanding plants, will plants like Anubius have trouble?

Whats the best time line for my lighting? ie. a break dureing the day? overall time during the day?

What's the best low growing "carpet" plant to keep...in your opinion of course?

I've heard a hundred different answers to these questions and I understand that many options could work... Please help me to decide what I want.

[artw]

Well, your best bet is to get yourself a nice set of T5 or Compact fluorescent lights.   I prefer the Current brand, you can get them online in the US pretty cheap. You want to get yourself at least 4x65watts of 10,000k lights on that 75 and you should be good to go.  Big Daddy should be able to set you straight T5 wise if thats the way you decide to go.

[pitabread]

I prefer watts-per-square-inch over watts-per-gallon.  I made a chart such to that effect:



So for a 75 gallon, 149 watts is "medium light" and 223 is "high light".  6500-10000k bulbs are good.

The Anubius should be fine in higher lighting.  I have a giant Anubius that thrived under 130 watts of lighting in my 48 gallon.  And I've got some Dwarf Anubius that is doing well under 27 watts in a 5.5 gallon.

For timing, I have two sets of lights.  One set comes on for 10 hours a day, while the other comes on for about 6 hours.  That way I've got a couple hours in the morning and evening of lower light, with the "bright" period in the middle. 

[BigDaddy]

As far as timing goes, in a high light CO2 injected tank, 12 hours of continuous light is all that is needed.

For bulb temperatures, anything over 5,000K is good enough.  Beyond that, its really a question of what you think looks the best... the plants themselves don't really care

If you go with T5HO or CF bulbs, in either configuration, 4 bulbs will give you a nice "medium-high" light tank.  I have run 4 x 55W CF and am currently running 4 x 54W T5HO, and the T5HO provides just a bit better growth than the CF bulbs did (closer internodes, red colouration lower in the plants, etc...).  The other bonus with T5HO is that you can set them up in a much smaller amount of space than their equivalents in CF bulbs and they will run the full length of a 4 foot tank instead of having to "pair up" a set of 2 foot CF bulbs.

As far as low light plants go, they will do just fine in higher light.  However, slower growing plants like anubias can and will develop green spot algae on the leaves if exposed to direct light.  Plant them in such a way that a fast growing stem plant shades them slightly, and you won't have to deal with algae on the anubias leaves.

As far as carpetting plants grow, many people will say glosso.  However, it is a MAJOR pain pruning wise...  Honestly I really like E. tellenus as a carpet plant, and there are some nice crypts that will propogate quickly enough to establish near carpet levels if cared for properly.

[RedFish]

Pitabread - correct me if I am wrong, but your system does not take height of the tank into the equation.

You have a 20 gallon long, which is only 12 inches high, requiring more light than a 20 gallon high, which is 16 inches tall.
On your chart, a 29 gallon which is 18 inches tall requires the same lighting as the 20 gallon long.

I don't think this is correct.......??

[pitabread]

Pitabread - correct me if I am wrong, but your system does not take height of the tank into the equation.

No it doesn't, but it is only intended as a rough guide.  I wanted something to convert the WPG rule to smaller or larger tanks.  The only restriction was I limited the list to tanks 24 inches high or less, though.

But realistically, there are so many variables in lighting.  Types and quality of bulbs, type of reflector, wattage, height of tank, height from tank, etc.