Another WPG Q...?

I would think you would use the water amount that you light up. Even at that the light depends so much on the type of bulb T5HO, PCF, etc. Then add to that the type of reflector. Why not just see how your plants are growing and add light as you need it?

'cos lights are bloody expensive down here!! ](*,) Man, you Americans get it easy

Seriously, even cheap import crap lights start out at around $70...and don't even think about ADA gear! It ridiculous. I've actually bought a 2x39w T5 off evilBay that should arrive soon, just for this tank. That was super cheap at $85 for a 3ft light. My intention is to just run one 39w and keep one spare, but I just needed to know what my Watt ratio would be... You confirmed my theory, though, that I'd only need be concerned with the areas that I intend to illuminate, so cheers for that.

Anyone else have any thoughts on this??

I would forget about watts per gallon.

If thats all the plants you intend on having a single 39w bulb will work great even if it is lousy reflector.

There will be "some" more plants added, as I get the system up and running. Not many, just some J.Moss, and maybe Anubia or somesuch...

You don't need a lot of light. Your compartmentalized aquarium would be considered a singe aquarium. I would recommend strip lights of some sort. Any light type will do; the higher the intensity of light and the better the reflector(s), the less light you need in terms of wpg. What are the dimensions of your aquarium?

800x375x300mm, internal dimensions. Each compartment is 200x245x295mm...

Avalon said:

Your compartmentalized aquarium would be considered a singe aquarium.

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You mean each compartment is considered a single aq. or the whole tank?

ghengis said:

There will be "some" more plants added, as I get the system up and running. Not many, just some J.Moss, and maybe Anubia or somesuch...

Click to expand...

Hey Buddy, I have a Java Moss/Anubia tank with 20w, 29G, so 0.69 WPG and it is doing great. If you only plan on having those plants, you're light setup is OK.

Why would putting dividers in make the lighting more intense? I know what you are asking, but cannot fathom why you are asking it.

Your light is measured as the lighting over the complete volume of water it is illuminating. You can put a divider in every 2". It doesn't matter, the light intensity and the total volume of water remains unchanged....24w over 24g is 1 wpg. 24w over 4x6g is 1 wpg. A more effective measure is LSI (Lumens per square inch), which measures light intensity over a footprint, and your footprint isn't changing by adding the dividers. The rear "overflow" section, yes, changes footprint... is that where you got the 1.6 wpg from?

The only consideration I can think of is that your dividers are black and not clear. This hurts you, as the light cannot spread properly - meaning you may (will) have lower effective lighting rates versus an un-compartmentalized and equivalently sized aquarium.