# how much is too much light?



## pyrrolin (Jan 11, 2012)

Usually people don't have enough light. I am wondering about the other end, too much light. How much is too much?

Not amount of time, the amount of light, just to clarify


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## Darkblade48 (Jan 28, 2008)

pyrrolin said:


> Usually people don't have enough light. I am wondering about the other end, too much light. How much is too much?
> 
> Not amount of time, the amount of light, just to clarify


Well, there isn't really "too much light" per se; you could have a metal halide light over a small 1 gallon aquarium.

The only issue is that you would need to have an extremely high rate of CO2 and excellent fertilization. Any slip up would instantly result in an algae bloom.

Not to mention that algae would probably grow much better anyway.

I would say anything over ~100 umol PAR/square inch is too much.


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## pyrrolin (Jan 11, 2012)

would 4 t5ho lights over a 15 inch high tank be too much?


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## Darkblade48 (Jan 28, 2008)

pyrrolin said:


> would 4 t5ho lights over a 15 inch high tank be too much?


Yes, most definitely.

Unless you plan to suspend it very high above the aquarium?


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## solarz (Aug 31, 2010)

When you're spending more money on electricity than you need to, then it's too much light.


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## balutpenoy2oy (Feb 17, 2011)

solarz said:


> When you're spending more money on electricity than you need to, then it's too much light.


Very right...


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## getochkn (Jul 10, 2011)

I can grow most plants in my various tanks with nothing more than CFL twisty bulbs in either standard hoods, DIY fixtures, reptile domes, whatever I can get a CFL bulb into, it goes over a tank. I have no more tube lights, just CFL's and have 9 tanks lit by them, growing everything from a Val jungle to a dwarf hair grass carpet. No CO2 on any tanks.


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