Lux Rule Vs Wpg Rule For Light Need To Grow Plants

[Renate]

Here is a link for info on how much light is need by an expert:
http/www.rexgrigg.com/mlt.html

 

[Wolfenrook]

What made you think he is an expert? lol. Never heard of him, and he doesn't show any credentials such as qualifications or the like anywhere on that site. Sorry, but it's just another planted aquarium blog.

If you are looking for folks who are well known in the planted tank hobby you want Tom Barr, George Farmer et al.

Ade

 

[aaronnorth]

lol, i see where you are coming from but he does know his stuff, he is usually on the barr report quite a lot.

 

[piper]

I work as a building services engineer and any lighting design that is done for offices and shops is done on Lux. No one would ever do a lighting design based on watts.

I have been looking into lux calcs for aquariums. I'm just trying to work out how the equations we have will differ for water rather than air.

 

[lljdma06]

I like this site in particular.

http/woo.gotdns.com/Aquarium/Lighting.htm

Basically the same stuff as the other article, but I really like the consideration of other bulb types besides T8s. The little tank calculator is a helpful plus too, but you have to scroll and look carefullly, it's kind of hidden.

llj

 

[Renate]

I like this site in particular.

[URL="http/woo.gotdns.com/Aquarium/Lighting.htm"]http/woo.gotdns.com/Aquarium/Lighting.htm[/URL]

Basically the same stuff as the other article, but I really like the consideration of other bulb types besides T8s. The little tank calculator is a helpful plus too, but you have to scroll and look carefullly, it's kind of hidden.

llj

Well, glad someone else sees that going by wpg is not best for deciding how much lighting is needed. Going by the wpg rule seems so wasteful of energy. I was thinking so because the depth of the tank affects how much light gets to the plants and a 20 gallon long is not the same as 20 gallon deep. I didn't think the size of the bulb made a difference.

Great link!!

 

[Dave Spencer]

Renate, you are telling most people what they already know. WPG is very vague and, like I said, if you want to know what light your plants are getting, use a PAR meter.

Most people have a feel for how much light they are going to need.

Dave.

 

[lljdma06]

Renate, you are telling most people what they already know. WPG is very vague and, like I said, if you want to know what light your plants are getting, use a PAR meter.

Most people have a feel for how much light they are going to need.

Dave.

Yes, WPG is vague and inaccurate, but I'm too cheap for a PAR meter and too lazy to do the math required by the calculations for other methods, so WPG it is! Just some division and a little gestimating. Good enough for me.

Like Dave says, after a while, you learn to have a feel for it and you learn to watch the plants.

Plants doing well = you are ok
Plants not doing well = something's up and most of the time it boils down to two things, CO2 levels or lighting levels. If those are ok, then you look at your macro nutrients, then your micros.

llj