[Commodore 64]

IN a nutshell...I'm running 2 32w T8 6500k bulbs.

Bulb 1: 4x ODNO
Bulb 2: 2x ODNO

Browsing the web and forum threads, I find differing opinions as to what kind of light this setup would be providing my tank. This is my first planted tank, I'm not using CO2 (yet), but I am using Seachem Ferts and Excel.

I have read that 4x ODNO T8 will put out ~ 69w of light, but the lumen output makes it the equivalent of 125w as written: For a planted tank - you can consider each F32T8 bulb to be the equivalent of 125 watts (overdriven with a four bulb ballast per bulb) - enough to grow most plants in a 55gallon tank. Two of these bulbs (again, each with their own ballast) would be enough light on even a 75 gallon to grow intense light plants. -- quoted from here.

Basically I'm trying to figure out whether my tank is low light, moderate light, or what. My substrate is ~ 20-inches below the light fixture.

Does anyone have any opinions?

 

[SpeedEuphoria]

Here is a good thread with some actual measured info.
http://www.plantedtank.net/forums/lighting/21257-odno-measurements-power-consumption-vs-light.html

Currently I have a 55G and I am also running 2 32w T8 6500K bulbs(GE). I have them both 2x ODNO. I find this is good light, prob around medium, I figure its ~100w total. I'm using a shoplight, although its not a typical one as it has decent built in reflectors. I am not using CO2 but have started using Excel.

On yours since you have 2 separate ballasts, then you could use the info in the chart and figure you are getting 69w from the 4x and 54w from the 2x, which means 121w total(it all depends on the ballast factor of your ballasts). Now this in itself is medium light which would greatly benefit from CO2. Depending on the reflector or lack of one, you could have over medium light or under medium light IMO.

But it depends on how good your reflectors are and how high off the water surface the lights are as to there effectiveness.

 

[El Exorcisto]

I have 4 bulbs, each one overdriven 2x over my 55. I'm running two 6500K Phillips Daylights and two 5000K GE Sunshines. The light is intense enough to start my hygro difformis and val. americana pearling in under five minutes. I never really worry about the actual intensity when I see results like that so quickly. Halides may be more intense and have that sweet shimmer going on, T5s may be ultra-efficient, but you can't beat overdriven T8s for initial and maintenance costs over a 4' tank.

 

[Commodore 64]

I have 4 bulbs, each one overdriven 2x over my 55. I'm running two 6500K Phillips Daylights and two 5000K GE Sunshines. The light is intense enough to start my hygro difformis and val. americana pearling in under five minutes. I never really worry about the actual intensity when I see results like that so quickly. Halides may be more intense and have that sweet shimmer going on, T5s may be ultra-efficient, but you can't beat overdriven T8s for initial and maintenance costs over a 4' tank.

Ok, what exactly is pearling? I don't have CO2 yet, but I'll be getting a DIY Yeast setup running in the next few days which should be better than nothing. At this point I just dose with Excel (along with other Seachem Ferts.)

I have my shoplight mounted on an oak wood frame that I built, that rests on top of the tank...and I think it negatively affects the light that is reflected into the tank. I should paint the interior of it white, I'm sure that would help.

I question the amount of light I'm getting effectively, here is my current planting...

Hornwort (2 weeks): doing well, growing maybe 3/4-inch per day
Banana plant (1 month): growing new leaves and roots
Amazon Sword (1 month): growing new leaves, really took off in the past week
Java Moss (6 months): is growing well

Moneywort (1 month): growing slowly, leaning towards tank center (higher light?)
Echinodorus vesuvius (3 weeks): Some melted. Not doing much, but I see 2 runners are slowly growing and new growth has purple streaks.

Java ferns (2 weeks): no new growth but still green, I *think* they are pearling (like little ferns shooting off the underside of leaves)
Crypts (1 week): no new growth, some melting
S. subulata (1 week): some melting, no new growth yet

Dwarf Hairgrass, E. acicularis (3 weeks): dead, just disappeared, never grew.

 

[SpeedEuphoria]

Pearling is air bubbles on/under the plants. It means that the plants are doing well and you have enough of them to load the water to its max of O2.

If you do a water change you can see false pearling as the water prob has excess Co2 and you'll have bubbles all over.

At a minimum i would paint the inside of the hood white, it would be better if you could buy some roof flashing and make some sort of reflector then you could highly polish it or paint it white.

DIY CO2 if not working properly can cause algae issues if it fluctuates alot, so make sure to a good diffuser and get a solid mix thats as stable as possible.

 

[El Exorcisto]

I have my strips sitting on my tank, no canopy, just a couple sticks as intermediates. Pearling is caused by plants photosynthesizing fast enough to saturate the water around them with oxygen, causing oxygen bubbles (not air) to form under or between their leaves. If you have a 55, use two strips if you want the maximum amount of light... The tank can handle the footprint. You need CO2 if you want high lighting. Everything needs to be balanced, and you are out of balance if you are not running CO2 with high lighting levels. Homebrew CO2 is cute on a 10 gallon, but it gets old on a 55, trust me, I know. I have a Red Sea Paintball system and love it. Do yourself a favor and spend the coin on a cheap pressure system as soon as you can.

 

[Commodore 64]

I have my strips sitting on my tank, no canopy, just a couple sticks as intermediates. Pearling is caused by plants photosynthesizing fast enough to saturate the water around them with oxygen, causing oxygen bubbles (not air) to form under or between their leaves. If you have a 55, use two strips if you want the maximum amount of light... The tank can handle the footprint. You need CO2 if you want high lighting. Everything needs to be balanced, and you are out of balance if you are not running CO2 with high lighting levels. Homebrew CO2 is cute on a 10 gallon, but it gets old on a 55, trust me, I know. I have a Red Sea Paintball system and love it. Do yourself a favor and spend the coin on a cheap pressure system as soon as you can.

I'm moving to a 75g in the next couple weeks (55g center brace is broken, tank is bowing, and I've wanted a 75g for a while anyways).

After that investment, my next will be pressurized CO2. I want to see pearling!

 

[SpeedEuphoria]

I just fixed the center brace in my 55G, been holding for 2 months now(broken when I got it). If yours is broke now I would lower the water level till its stops bowing. Mine would bow but not leak when all the way full