# to much light?



## mkeevil (Oct 22, 2006)

Well my question is simple, I have seem a lot of posts about how many WPG... and wanted to know if I have too much light. I have a 58 gallon with 2 96 wat lights... so what would be 96 * 2 = 192 / 58 gallons = 3.3wpg? is this right?


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## hoppycalif (Apr 7, 2005)

The calculation is right. And, that is a lot of light. If you had 2 to 2.5 watts per gallon everything would probably grow as well, but slower, and the algae problem would be far less, especially with an 8 hour photo period vs. a 10 hour period.


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## mkeevil (Oct 22, 2006)

I don't have any Algae, I had some diotoms but there gone. Just though 1 light was too little and 2 lights was tooo much. Maybe some surface plants would bring down the light inside the tank a little?


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## Laith (Sep 4, 2004)

You're a bit on the high side (at least to my preferences) but if the tank is doing fine and you're keeping up with the plant needs in terms of ferts, I wouldn't bother trying to change it...


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## John N. (Dec 11, 2005)

I agree, if you can keep up with CO2 and nutrient needs then you should be fine with that amount of light. I would have a lower photoperiod time of around 8 hours if you are having algae issues.

-John N.


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## ruki (Jul 4, 2006)

Just remember that WPG is not a rule, but an estimate. It's +/- 50 percent or more depending upon the bulb type, bulb and reflector.

To get much better, we need cheap PAR meters with a green filter in front of them. A good setup costs over $1000 US! With all the interest, maybe someone will come up with something in the $100 range. Not holding my breath, but just hopefully dreaming 

Fortunately plants are pretty adaptave, so they do well inside a fairly wide range of light levels.


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## Newt (Apr 1, 2004)

Ruki is correct. The WPG rule of thumb is for NO fluorecscents. T8s and T5 (including CF/PC) have a greater intensity of light per watt and fewer watts would be needed with the old rule of thumb.


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