Will I need co2?

[V10]

Hey folks,

I just picked up an obrit lighting system for my setup, it comes with 2x96w bulbs, 1 daylight, 1actinic. I have a 46 gallon bowfront that is about 20" tall (freshwater).

I'd like to have the ability to get some medium light plants in my tank but can't afford a co2 system yet so I my question is at what point is pressurized co2 a must? I also don't mind putting the new light in storage until I can save up enough for a co2 system, but it looks so nice, i want to get it up, even if I have to power it down wattage-wise.

I'm planning to take the actinic bulb out and run just the 1 96w bulb by itself, which would put me at 2 wpg. Is co2 needed at 2wpg?

In the future, with co2, would you guys recomend equipping the unit with the 2x96w daylights(no actinic) or downgrade to 2x65w daylights?

(I did read the co2 sticky on this forum, it was great post, but would still like some feedback)

 

[czcz]

Compact flourescent is more efficient than T12 (see lighting sticky for Ozz's article and the AA thread), so when looking at wpg you have more like ~2.8 equivalent T12 wpg, and CO2 will certainly help. At your tank size, eq T12 wpg standards still hold up pretty well.

Maybe consider running one 96w 50/50 for ~1.4 eq T12 wpg? You'll probably grow some medium light plants with that light.

When you are ready for high light, 192w CF is pretty hardcore but is probably doable with enough determination and command of CO2/ferts. Worst case you could maybe run 2x96w for a noon effect, with 96w for the rest of the light cycle. Or, you could use 96w daylight and 96w 50/50 to lower the light level a little until you're ready for extremely high light.

If its possible to downgrade to a 2x65w fixture, it may be the best course of action. 65w CF would put you at ~1.9 eq T12 wpg, pretty perfect for what you want now, and 2x65w would certainly be high light.

There's the DIY CO2 or Flourish Excel options as well if so inclined. Many people are getting good CO2 ppm from DIY in similar tank sizes lately.

 

[V10]

Thanks for the advice, now when you say perhaps running a 96w 50/50, are you talking about a bulb that is half daylight, half actinic? or a dual temp daylight bulb? Sorry, still kind of new to the lighting lingo.

 

[Lonewolfblue]

A 50/50 bulb is half daylight and half actinic. The actinic half won't go towards the w/g calculation.

 

[mr funktastic]

50/50 means half daylight half actinic. u got it right. by doing this u will only have 48 usable watts of light if u run one bulb. that will put u just above 1 WPG. if u run 1 full daylight bulbs at 96watts u will be at 3.56 WPG. to high to run without co2. 1.7 WPG with running the 50/50. that would be your best bet untill u can get the co2. hope that helps

 

[SkullJug]

IMHO strap it all on and go with it!!!!

There are ppl out there who would love to 3.5 WPG (I run at 4.4 and it rules!!!) DIY c02 is really, really easy. I run a 75g tank and sit at 20ppm c02 (Three bottles with a pretty slow brew) all you need then is to sort out your fertiliser and there is nothing you won't grow in your tank - Get yourself a nice lawn if you want.

 

[mr funktastic]

lol 3.5 watts is if he only runs 1 bulb. he is lookin at 7 WPG if he runs the two 96watt bulbs with daylighs. i think that is a litrle overkill. u would need to be dosing ferts by the hour to keep up with that lol. if u want to try all the power to ya... literally. give your fihs some sunglasses sit back and get a tan!!! lol

 

[V10]

wow, am I calculating wrong, I thought my max possibility would be 4.17 wpg if I ran 2 96w daylight bulbs. or am I missing a conversion/multiplier needed for PC bulbs?

I was going by total watts divided by gallons, so (96x2)/46=4.17

Or if I could use 65w bulbs on the same fixture, I'd have (65x2)/46=2.82

Going to read that lighting sticky that czcz referred to now.

 

[Purrbox]

Your calculations are fine. The problem is that the WPG estimate is based on NO Flourescents. To compare the CF's you have to convert the wattage to the equivalent NO Flourescent Wattage. This is done by multiplying your wattage by approximately 1.35.

 

[mr funktastic]

i thought it was 1.71? but i am sure that is based on 100% reflection though. with pc bulbs u get a lot of light for your buck. i am running t-8s which the conversion is somewhere around 1.41. someone please correct my calculations if i am wrong

 

[Wizzard~Of~Ozz]

The conversion is based on the bulb, reflection is irrelevent in comparing fixutres, it's safe to assume that most fixtures have the same efficiency in reflectors.

PC's do NOT output more light then a T8 bulb. They are great for 2 reasons. 1: compact location and 2: bulbs work until they are dead.

It's really hard to get adequate light over a tank using T8's or T12's..

I would agree with running a single 50/50 bulb. When you can afford Co2 (DIY is not practical on larger tanks, even with it on mine I was plagued with algae..) then put the daylight bulb in the free slot (1 50/50 and 1 daylight) this will get you ~ 4.2WPG (if you prefer that measure) and should be a great tank if you keep an eye on the nutrient levels..