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I was unsure of whether or not to start a new thread on this topic, but I think it can be of use to a lot of people out there wanting to start small planted tanks.

What do you all think about lighting small planted tanks? I've heard before that the WPG rule does not apply to small tanks, say 10G and under, so you need to go above and beyond what you normally would. For example, I was running a 2.5G tank with a 9watt PC light over it, but nearly 4WPG is still considered low light for a nano. I'm currently setting up a 7 gal. tank and I have the option of using a 28watt PC light I have - at 4WPG on a 7G tank, is this still considered low light? Or is it in the desired medium range? Or is this high enough to cause problems without the addition of CO2?

Maybe the labels low/medium/high are worthless in this situation. What is enough for a relatively low maintenence tank? What is too much?

Thanks for any thoughts, this is completely open to any discussion/ tangents. Just wanted to make a little centralized place to collect some info for the time being

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Back in the saddle!

NowherMan6,

I think there are not enough hard facts out here that would enable a definite answer. This whole WPG thing seems to become a paradox on small tanks.

I would assume that you will be able to grow medium-light requiring plants, but I got nothing to back this up.

I would assume really small tanks lose a lot of light through the glass as the tank substrate area is so small. The larger the tank the more light can actually hit the substrate.

Sorry about that,

Ingo

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Proud Member of the New Jersey Aquatic Gardeners Club

This whole WPG thing seems to become a paradox on small tanks.

Right, which is why I just want to be able to get rid of some of the confusion... WPG isn't a good way to look at it, maybe we just need to look at it in terms of watts, period. I dont know.

I just feel there's a danger in saying WPG doesn't work, therefore you can have a large amount of light over a small tank. My worry is that I put that amount over the tank, and then BOOM! GW again, plus hair algae and other PITAs.

And also, if you up the lighting on a small tank, what does that mean for fert dosing and CO2. with 3-4 WPG on a larger tank CO2 and at least macros would be a must, but is the same true of smaller tanks? How does it affect our understanding of that?

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Back in the saddle!

Hey,

If I remember that right (and if not then I am underestimating to be on the safe side), Amano has a whopping 9WPG on his small tanks - you are not going to be high light

Ingo

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Proud Member of the New Jersey Aquatic Gardeners Club

Right, but does Amano add CO2, does he go through with the same fert regimen as with a larger tank? It's those other associated things that have me thinking (too much... )

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Back in the saddle!

"Right, but does Amano add CO2" - Yes

"Does he go through with the same fert regimen as with a larger tank?" - Yes

But you are not high light, a little excel and some leftover ferts from the big tank will do

Ingo

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Proud Member of the New Jersey Aquatic Gardeners Club

Watts is a measure of how much energy is used to power a light. Lumens is light output so I assume lumens is the better choice.

"A noble spirit embiggens the smallest man" Simpsons

bcwcat22,

That is true, but:

a) have you seen any Lumens printed on the common aquarium lights?
b) even then, what does that mean when comparing small to large tanks?

Ingo

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Proud Member of the New Jersey Aquatic Gardeners Club

Littlefish,

I see the issue of small tanks and I also have a 10 gallon with 2.6 wpg but I dont know how this varies because of size.
I have actual found that (at least at my hardware store) many products are caring lumens now.

"A noble spirit embiggens the smallest man" Simpsons

bcwcat22,

First of all you gave me a good idea (or not so good depending on the results). Maybe it would be worthwhile committing a thread that has the solemn purpose of listing Lumens for the individual bulbs from the individual manufacturers. It seems like a lot of work (if not even impossible) to get all the ones that we usually use in, but it might be worth a try.

Regarding tank size and WPG (or Lumens), did you see [link=This Thread]http://www.fishprofiles.com/files/forums/Planted%20Aquaria/66108.html" style="COLOR: #ff6633[/link]. It talks in rather detailed fashion about the different requirements to label a tank a certain light level based on size.

Thanks for the input,

Ingo

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Proud Member of the New Jersey Aquatic Gardeners Club

The reason the WPG thing goes out the window is due to the lower powered bulbs that will typically fit over a small tank.

The reason your 2.5 gal is low light is because of the use of a 9 watt bulb. 9 watts won't grow squat. It would be low light over a glass of water !!!!

If you are using a single 28 watt bulbs over a 7 gallon that's pretty good light. 2 X 14 watt bulbs would not be near as good depite being "mathematically" equal. See the point.

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Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.

I see your point bensaf - so basically there's a certain wattage that will grow plants well, no matter the size of the tank?

And I see your point about the 28W single bulb being better than the 2 14 W bulbs - but then my question is, dont YOU have a 5 gallon tank with 2 9W bulbs over it? Theoretically, shouldn't you be growing squat?

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Back in the saddle!

ok so to clear this up for myself (soon to be starting a 7g tank)

i have 2 spare 15W tubes that were over my 20g tank. over the 20g it was 1.5wpg (low light) over the 7 g, 1 would be 2wpg (low light?) 2 over the 7g would be 4wpg? can i call this medium or high? and will the single 15W over the 7g grow anything?

Cheers
Cynical

but then my question is, dont YOU have a 5 gallon tank with 2 9W bulbs over it? Theoretically, shouldn't you be growing squat?

Well it's 2 bulbs and a decent set of reflectors on the fitting. But it's just about the minimum I can get away with. Nothing too light hungry in there, Anubias, Moss, Crypts, Sags only one stem plant but that almost reaches the surface so is only a couple of inches from the light.

Tried Blyxa Japonica for example, didn't work at all.

Stuff grows but painfully slow and small which is a good thing. There's a couple of plant species which will survive in low light but basically become little Bonsai versions of themselves. I use them to my advantage. Even the Anubias do that in this tank. The leaves are tiny, about 1 cm. Maybe I've invented a new variety ultra pettite var. Bensafii !!!

Sags that grow short but very thick and wide in the big tank grow tall, thin and much less bushy in the small tank, forget about runners.

There's a very small selection of plants that will work in this tank.

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Some days you're the pigeon and some days you're the statue.

Remember that age and treachery will always triumph over youth and ability.