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Discussion Starter · #1 ·
I am obsessed - and thinking around the December timefram converting my 65G fresh to Live Planted.

I realize lighting and CO2 are important. I am wokring on better understanding CO2.

For lighting however, I am confused. For example:
"USA Nova Extreme 36" 2X39W T-5 10,000K - Freshwater"
http://www.bigalspets.com/Current-U...olor_map,price,size_name&searchRank=salesrank


^ Would be a properly sized light for my tank - However, that equals 78 Watts and far less than 2 WPG - I know WPG is not the golden rule, and many other variables come into play...but is this a sufficient source for most plants, or merely low light?

Please explain...
 

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The tank is 24 inches high. If you have 2 inches of substrate, a light sitting on top of the tank will be about 22 inches from the substrate. At that distance a T5HO, single bulb light, with a typical very good reflector should give you about 50 micromols of PAR. So, a two bulb light of that quality should give you 100 micromols of PAR. But, the Nova Extreme light doesn't have typical very good reflectors, so it should give you less light, perhaps 30-40 micromols of PAR per bulb.

You only need around 40-50 micromols of PAR to grow just about any plant you want to grow, as long as you also use CO2.

A tank that is 18 inches front to back depth will not generally get uniform lighting from a single bulb light, or even a 2 bulb light with close together bulbs, if the light sits right on top of the tank. If the light is raised a foot or so above the top of the tank you can get pretty uniform lighting. So, if you raised that Nova Extreme light a foot above the top of the tank, about 34 inches from the substrate, you should get around 30 micromols of PAR, which isn't enough light for many plants. If you compromise and raise it only about 6 inches above the top of the tank, about 28 inches from the substrate, you should get about 40-50 micromols, which is a very good light level to have.

Personally, I would consider a light with better reflectors, so I could raise it a bit higher, then run the tank with no glass on top - open topped. The disadvantage is the shadow of the brace across the top. That might convince me that a better idea would be to have Catalina Aquarium make me a custom light with two bulbs, but separated about 8 inches, so I could sit it on top of the tank, without getting too much light.

As always, there are many options available.
 

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Discussion Starter · #3 ·
The tank is 24 inches high. If you have 2 inches of substrate, a light sitting on top of the tank will be about 22 inches from the substrate. At that distance a T5HO, single bulb light, with a typical very good reflector should give you about 50 micromols of PAR. So, a two bulb light of that quality should give you 100 micromols of PAR. But, the Nova Extreme light doesn't have typical very good reflectors, so it should give you less light, perhaps 30-40 micromols of PAR per bulb.

You only need around 40-50 micromols of PAR to grow just about any plant you want to grow, as long as you also use CO2.

A tank that is 18 inches front to back depth will not generally get uniform lighting from a single bulb light, or even a 2 bulb light with close together bulbs, if the light sits right on top of the tank. If the light is raised a foot or so above the top of the tank you can get pretty uniform lighting. So, if you raised that Nova Extreme light a foot above the top of the tank, about 34 inches from the substrate, you should get around 30 micromols of PAR, which isn't enough light for many plants. If you compromise and raise it only about 6 inches above the top of the tank, about 28 inches from the substrate, you should get about 40-50 micromols, which is a very good light level to have.

Personally, I would consider a light with better reflectors, so I could raise it a bit higher, then run the tank with no glass on top - open topped. The disadvantage is the shadow of the brace across the top. That might convince me that a better idea would be to have Catalina Aquarium make me a custom light with two bulbs, but separated about 8 inches, so I could sit it on top of the tank, without getting too much light.

As always, there are many options available.
That is half the fun, and all of the frustration haha.

Amazingly, I understood your post. Is open top preferred in many cases? Aside from fish known to jump, do you worry about School fish such as Danios and tetras suicide tendencies with an open top?

I was actually curious as to how a light would distribute evenly throughout the tank over glass especially with the hinge in the middle of the glass to allow opening for feeding...
 

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The tank is 24 inches high. If you have 2 inches of substrate, a light sitting on top of the tank will be about 22 inches from the substrate. At that distance a T5HO, single bulb light, with a typical very good reflector should give you about 50 micromols of PAR. So, a two bulb light of that quality should give you 100 micromols of PAR. But, the Nova Extreme light doesn't have typical very good reflectors, so it should give you less light, perhaps 30-40 micromols of PAR per bulb.

You only need around 40-50 micromols of PAR to grow just about any plant you want to grow, as long as you also use CO2.

A tank that is 18 inches front to back depth will not generally get uniform lighting from a single bulb light, or even a 2 bulb light with close together bulbs, if the light sits right on top of the tank. If the light is raised a foot or so above the top of the tank you can get pretty uniform lighting. So, if you raised that Nova Extreme light a foot above the top of the tank, about 34 inches from the substrate, you should get around 30 micromols of PAR, which isn't enough light for many plants. If you compromise and raise it only about 6 inches above the top of the tank, about 28 inches from the substrate, you should get about 40-50 micromols, which is a very good light level to have.

Personally, I would consider a light with better reflectors, so I could raise it a bit higher, then run the tank with no glass on top - open topped. The disadvantage is the shadow of the brace across the top. That might convince me that a better idea would be to have Catalina Aquarium make me a custom light with two bulbs, but separated about 8 inches, so I could sit it on top of the tank, without getting too much light.

As always, there are many options available.
Thank you for this explanation! I am in the same boat as Realistik; overwhelmed by the information out there for a tank of the same depth and height. This was so helpful!
 
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