Lowering Light Levels

[ShinySideUp]

My new tank has 80 watts of light but only a very few plants and to be honest it's a bit bright. Any suggestions as to how to tastefully lower the light levels?

Martin

 

[Aqua Marine]

Buy a lower wattage bulb that fits the hood.

 

[ShinySideUp]

Buy a lower wattage bulb that fits the hood.

It's not that simple since a set length of fluorescent tube seems to be a set power output so a 42 inch light is 40 watts. You can't get a 42 inch tube that's, say, 20 watts.

 

[DrRob]

WHat sort of tubes are you talking about? T8's or T5's or other?

There are different wattage tubes available at different lengths.

 

[micko]

There really should be different wattage tubes. Even a non aquatic reccomended tube will work.

 

[alihar]

Get some floating plants they will diffuse the light.

 

[adzilla88]

Would a reflector work to diffuse light? I'm no expert! Just a thought...

 

[snazy]

WHat sort of tubes are you talking about? T8's or T5's or other?

There are different wattage tubes available at different lengths.

Not really, you can't interchange a 15W tube for 40W tube. All you can do is upgrade to lower or higher "Lumen" tubes and other parameters, but at the same wattage as wattage is unfortunately proportional to lenght.
If you want something not as bright, then exchange for a different type. Brightness has nothing to do with what plants need. What humans see as bright, to the plants it don't matter. Plants use different portion of light than the one we see.

 

[ShinySideUp]

Yes, I think the floating plant option is probably the easiest and the cheapest; I shall do that and use some sort of tether to prevent them all ending up at one end of the tank.

Cheers

Martin

 

[CezzaXV]

You can buy dimmer plugs that will limit the amount of electricity, and thus the light. They're around £5 on eBay. Not sure if they'd damage your lights though.

 

[Aqua Tom]

You can buy dimmer plugs that will limit the amount of electricity, and thus the light. They're around £5 on eBay. Not sure if they'd damage your lights though.

They wont work on flourescent lights. You can get dimmable flourescent fittings but they are mega expensive.

Tom

 

[three-fingers]

Floating plants will very quickly grow to shade the tank and do wonders to water quality too .

The reason they grow so well is their leaves are right up next to the light and have access to air - CO2 diffuses into the plants leaves much faster in air.

They are usually just a few £ off eBay .

 

[stu40]

There's Amazon Frogbit for sale in the classified section if you're UK based

 

[ian]

if it 'looks' to bright, you are probably looking at the wrong Kelvin for your eyes. You may just get away with getting a different Kelvin level bulb.

heres the Kelvin rating

all bulbs are measured this way, Kelvin is for aesthetic use only. I run 2 x 7500 k in my tank and that for me is great, very crisp and clean.

also heres a place for cheap bulbs

http/www.lampspecs.co.uk/

 

[snazy]

Theorethically the higher rated bulbs in Kelvin (bluish) penetetrate the water better than the lower ranges, so it is better for plant growth, and of course the more Lumen the better, regardless of the wattage.
But another important factor is the PAR. Basically, it represents the type of light needed by plants for the process of photosynthesis, in other words the spectrum at which the lights operate. Human eyes are sensitive to bright yellow/greenish light which not at all used by the plants and is in the spectrum of 500-600nm. What we see as orange/reddish is the light needed for in photosynthesis, and this is in the range of 650 to 670 nm and 430 to 475 nm.
Therefore taking all in mind, you don't actually need bright lights for your aquarium, unless you are going to read a book inside it