Plants, light, algae

[irishspy]

Hi all,

For the tank I want to get (a 40g rectangular), I've decided on Coralife 96w, 6700k compact fluorescent fixture on legs. (Here's the link.) So, I have some questions:

• This works out to 2.4 wpg. Is this too much light for low-light plants such as anubias or various crypts?
• Is 2.4 wpg considered "medium light," "medium," "medium high," or ... Plant Geek uses several gradations like that, but I can't find where they list the break-points.
• What other plants would do well at this level lighting? ("Well" means "thrive and look pretty, but doesn't have to grow like a weed.")

Also, will I have an algae problem with this much light, and is CO2 required? I plan on using fine-grained gravel with laterite mixed in the lower portion of the substrate.

I'm basically a fish-first person who thinks live plants provide a better environment for the fish, so I want to take care of the plants so they'll be healthy and pretty, too. Any and all advice welcome.

Thanks! :clap:

 

[Cory Keeper]

Yes, with taht kind of lighting I would go with a CO2 system, pressurized, should keep the algae in check.

usually most people list 2 1/2 WPG in the moderate lighting.

Mine is 2 1/4 WPG, and plants do alright, Don't look for crazy growth though.

 

[jmhart]

In my experience, plants that are low light grow fine at low light, but higher light levels don't hurt.

And yes, you'll need to add co2 and to start thinking about adding ferts.

 

[jones57742]

irishspy

You have "really done your homework" and hence I have only limited comments/input

For the tank I want to get (a 40g rectangular), I've decided on Coralife 96w, 6700k compact fluorescent fixture on legs. (Here's the link.)

• 
  
  [1] the standard 40G tanks sizes of which I am aware are not 36" in length. Pls Ref
  http://www.thetropicaltank.co.uk/tanks-us.htm
  
  [2] if you are "like I am" you will not be happy with the 6700K bulbs.
  These bulbs are what I term "grow light" bulbs and theoretically mimic sunlight.
  IMHO their dullness is not appealing.

This works out to 2.4 wpg. Is this too much light for low-light plants such as anubias or various crypts?

No.

Is 2.4 wpg considered "medium light," "medium," "medium high," or ... Plant Geek uses several gradations like that, but I can't find where they list the break-points.

Yes: it does seem like Voodoo but IMHO 2.4WPG for a 24" deep tank is "medium".

What other plants would do well at this level lighting? ("Well" means "thrive and look pretty, but doesn't have to grow like a weed.")

IMHO I would start with these.

Also, will I have an algae problem with this much light ...

Algae is principally due to over feeding, lighting periods of too long a duration and under fertilization with Seachem Flourish.

Yes. You will probably have to deal with this mess but after your first "rodeo" you will have a much better idea of how to avoid it.

This may be what it looks likes the first time it happens to you:

... and is CO2 required?

IMHO: not for your initial attempt at a planted aquarium.
This was my aquarium after approximately 6 months without CO2 but with Flourish fertilization.

I plan on using fine-grained gravel with laterite mixed in the lower portion of the substrate.

About the only thing which my LFS did correctly when he set up my tank (before I knew better) was the construction of the substrate. (Please note that my tank is 30" deep).

The following depths are very approximate:

• 
  [1] 1" of 1/4" aggregate overlaid by;
  [2] 2" of laterite mixed with 1/4" aggregate overlaid with
  [3] 1" of 1/4" aggregate.
  
  
  

  I'm basically a fish-first person who thinks live plants provide a better environment for the fish, so I want to take care of the plants so they'll be healthy and pretty, too.

  I am also but a nice planted tank is also very aesthetic to me.
  
  
  Getting back to fixtures:
  
  I have had very "good luck with" and enjoyed a 10000K and a 7100 in two Current USA PC fixtures.
  
  TR

 

[Mgamer20o0]

In my experience, plants that are low light grow fine at low light, but higher light levels don't hurt.

And yes, you'll need to add co2 and to start thinking about adding ferts.

just grow faster.

 

[TwoTankAmin]

I will have to disagree with most above. Slow growing, low light plants, when that is all that is in a tank, will become algae magnets in that amount of light. Adding co2 won't help re algae imo. Adding some faster growing plants and plants that can shade the anubias some will change the equation.

As to what level of light that 96w fixture really is providing is dependent upon the type of reflector in it. 50% of the light emitted but the bulbs is going in the wrong direction, so how much can be redirected into the tank is important.

As a basic guideline I use the following rough scale for fluorescent lighting: low light= 1 wpg, moderate light = 2 wpg and high light = 3 wpg. This will all be mitigated by the depth of the tank involved, the type of bulb in use, the nature of the reflector and then the physical configuration used. (Is all the light from one large bulb or is it spread across front and back and side to side with several smaller bulbs?) If your pick for a light has a decent reflector, I would say you will need to be adding some level of co2 and dosing nutrients and growing a lot more than anubias, crypts and ferns..

 

[irishspy]

Thanks for the advice guys, it's been helpful. :clap: Jones, the tank dimensions are listed at 36x15x16", so the light fixture should fit. And my prior tanks had a spot-algae outbreak like the ones in your picture. Drove me nuts. :wall:

Sounds like I should start reading up on CO2 .... :read: