lighting advice please :)

[vromanowski]

I want to start adding plants to my aquarium, but the more I read about lighting the more confused/frustrated I get. I don't know if I need to buy a whole new fixture, or just a new bulb, or if my current lighting is enough for the average/common in-store plants. but here is what I have.

on the bulb it says:
8,000 K
17w
T8
24"

on the fixture:
30" fluorescent
120 volt - 20 watt - 60 hz

misc info:
tank - 36 bow front
substrate - 3 inches pool filter sand
depth to sand: about 17"

I plan to do DIY CO2, already have some root tabs, just need help with the lighting!

 

[underdog5004]

Ok, the numbers on the fixture are probably maximum recommended numbers.

The numbers on your bulb are what you should pay attention to.

8000k means it's putting out light in a spectrum that plants crave, like brawndo.

17w means 17 watts of power is used to generate the light (or the load of light, w/e). Regardless, it's a number you use when figuring out how much light you have in the tank. 17 watts of light over 36 gallons of water is extremely low light, something like .5 watts per gallon. Expect slow growth with plants that don't need a lot of light. Don't do CO2 or ferts until you get the light rating up to at least 1 watt per gallon, because they won't help, light is your bottleneck

Hope I could help

 

[jsoong]

There may be a mislabel on the fixture, or someone had MacGyver it - you can't fit a 24" tube in a 30" fixture. If this is an old tank, chances are someone modified the fixture or swapped in the ballast from a longer tank.

At any rate, that is extreme low light for your tank. You can prob. keep Java Ferns alive, but not much else. And the plants prob won't grow much at that light level. So no CO2 or ferts. needed at all.

If you really want a nice planted tank, you will need to upgrade your fixture. Something in the 50-60W range would be nice. Although if you are going high tech (CO2) & high light, going to a 120-150W fixture is not out of the line.

 

[vromanowski]

thanks guys it was a lot of help. i went to my LFS and bought a new fixture, i'll post some pics when it's all set up

 

[mfdrookie516]

what fixture did you get?

 

[vromanowski]

it's a Coralife t-5 series
1 x 18w full-spectrum fluorescent bulb, says it's high intensity output
1 x 18w 6700K full-spectrum "plant lamp" (prob a gimmick), also high intensity

i know that's only 36 watt, but it's the best my LFS had, and it was a decent price. so with 28 actual gallons (3 inches sand), thats 1.28 watt per gallon.
Also if that's not enough I can still keep the other fixture with the 17w bulb running, 53w total so that would be 1.89 w/g. i should be alright, right?

 

[runninwoof]

thats a t-5 light. very nice! wpg doesnt work with t-5 lighting. you will be in a nice medium light range. and 6700k is = the sun at noon (i think) so its a good bulb. no gimmick there

8000k means it's putting out light in a spectrum that plants crave, like brawndo

I JUST DIED LAUGHING!!

 

[vromanowski]

yeah im hoping it going to be enough, dude at the store insisted it would be, just the 36w seemed low.

why doesn't the wpg rule apply?

and yeah the sucker is bright, accidently blinded myself with it lol

 

[runninwoof]

the wpg rule was used for normal output lighting. now t5 lighting blows the pants off the normal output.

 

[jsoong]

T5-HO (that's what you have) are more efficient than normal output (T12) fluorescent.
Roughly, T5-HO put out 1.6x more light per watt compared with a T12 (depending on reflectors).

So your light fixture will put out something like a 55W NO fixture. That should put you in a nice medium light range. High enough for a wide selection of plants But low enough that you don't necessarily have to go CO2.

 

[vromanowski]

aweomse ty.
i'm thinking about taking the one bulb out and replacing it so theyre both 'plant' bulbs. would this be a good idea?

 

[runninwoof]

no, the plants can benefit from diferent spectrums of light.

 

[Craigthor]

There may be a mislabel on the fixture, or someone had MacGyver it - you can't fit a 24" tube in a 30" fixture. If this is an old tank, chances are someone modified the fixture or swapped in the ballast from a longer tank.

At any rate, that is extreme low light for your tank. You can prob. keep Java Ferns alive, but not much else. And the plants prob won't grow much at that light level. So no CO2 or ferts. needed at all.

If you really want a nice planted tank, you will need to upgrade your fixture. Something in the 50-60W range would be nice. Although if you are going high tech (CO2) & high light, going to a 120-150W fixture is not out of the line.

Actually 99% of all 30" lighting on the market uses 24" bulbs the only exception would be T8 or T12 lighting. All CF, T5NO and T5HO fixtures use 24" bulbs either centered in the fixture or offset from each other to try and compensate for the extra ligth spread of the tank. Based on the information given sounds like a T5NO bulb or possibly a T8.

Extremely low light but if the OP sticks to the use of Java Ferns, Anubias, Wisteria, Hornwort, and some mosses they can acheive growth eventhough it may be slow.

Craig

 

[jsoong]

Actually 99% of all 30" lighting on the market uses 24" bulbs the only exception would be T8 or T12 lighting.

The OP states it was a T8 ... that's why the label doesn't make sense.

 

[vromanowski]

yes it's a t8, i just gave you guys exactly what the bulb/fixture had on them. it hasn't been modified or anything, it came with the tank (new), but i have the new fixture now so it's all good

 

[Craigthor]

The OP states it was a T8 ... that's why the label doesn't make sense.

Makes perfect sense, T8's are available in 17W jsut did a quick google search and here is one:

GE Ecolux T8 17W 86 CRI Fluorescent Light Bulbs, 17-Watt Eco Fluorescent T8 17W Lamp, T8 Fluorescent

But they are also available in the standard 15 watts as we are all used to:

Amazon.com: Philips 391086 F15T8/COOL WHITE PLUS/24 ALTO Straight T8 FluorescentTube Light Bulb: Home Improvement

The 17 watt bulb has a much higher CRI rating and probably provides better light intensity. Even though its only a couple watts more.

This would be similar the the CF where there are 55/65 watters both fit the same fixture jsut one is slightly moer overdriven by the ballasts capabilities.

Craig