Can I Achieve More Wpg?

[PortWash]

I am still learning about planted aquariums and am trying to get maximum lighting CO2 & nutrients. Let me start with I have a 29g tank with a dual tube 18â€￾ hood. I am operating the nutrafin Co2 system. Last night I did a 50% water change and added the recommended dosages of KNO3 and KH2PO4. For lighting I am using two Flora Glo T-8 Tubes that provide 15 watts each. After reading the pinned post on lighting and calculating that puts me at 1wpg [(15*2)/30]. So I began to look for a higher wattage 18â€￾ bulb. I came across http/www.lightbulbsdirect.com/page/001/CTGY/Plant which has an extensive array of light bulbs and found that they have 18â€￾ bulbs with CRI of 90 yet still a wattage of 15. Thus is my current lighting sufficient? Should I purchase the bulbs from the website? Or is there somewhere I can purchase 18â€￾ bulbs with higher wattage?
Am I missing something? Your input is appreciated

 

[jesseoneill]

I'm no lighting expert, but here's what I do know; feel free to correct me anyone if I'm wrong.

For standard fluorescent tubes, wattage related to length. Thus, 18" bulbs will be 15W bulbs no matter what. As far as I know, CRI is related more to light quality/color rather than light intensity (similar to the bulb's Kelvin rating). If you want more wattage above your tank, generally the only way to do so is by adding/upgrading fixtures. I'm guessing that the dual hood you have probably doesn't leave you with any additional space to add an extra light fixture, so you might want to consider a complete hood upgrade in order to bring more wattage into the space you have available. Both Coralife and Current USA make fixtures that are a good balance of price and quality and would allow you to put a 30" long 1x65W or 2x65W hood above your tank. AH Supply is also a popular option, and they offer a number of lighting options that would fit your tank well.

 

[PortWash]

You are correct in that my hood does not currently offer me any room for expansion. If i get a source of lighting longer than 24" (which is the length of my tank) wont that light be wasted thus lowering the wattage applicable to the calculation of wpg? Also if i add say a third 18" at 15 watts that is 45watts 45/30 = 1.5WPG still far under optimal. Also in looking at longer tubes, 36" provides 30 watts which i would need 2 or 3 to achieve 2 to 3 wpgs but as i referencced before wont that calc be wrong b/c 12" of each will not be over the tank? Thus can I not reach 2 or 3 wpg with my current tank?

 

[jaarus]

This is all based on T8 bulbs....and expansion.
What about replacement?

You could get 22" 55w T5 bulbs (you would need a new lighting starting unit as well mind you) and then DIY it into your hood.
I got mine for about £35-40 I think (for bulb and lighting unit).
Or 18" I think it was 36w? - same price near enough.

Could you remove the T8s and put in a t5 and starting unit? Or two??

36*2/29 = 2.48 WPG
55*2/29 = 3.79 WPG

That would give you way more light!!!
Good DIY hood builing guides in the DIY section - might be worth taking a look?

 

[PortWash]

This is all based on T8 bulbs....and expansion.
What about replacement?

You could get 22" 55w T5 bulbs (you would need a new lighting starting unit as well mind you) and then DIY it into your hood.
I got mine for about £35-40 I think (for bulb and lighting unit).
Or 18" I think it was 36w? - same price near enough.

Could you remove the T8s and put in a t5 and starting unit? Or two??

36*2/29 = 2.48 WPG
55*2/29 = 3.79 WPG

That would give you way more light!!!
Good DIY hood builing guides in the DIY section - might be worth taking a look?

very nice thanks. I will definitely look into it.

 

[PortWash]

So I looked into it: this is what I am thinking:

(2) 24" Aqualight T5 Double Linear Strip Light

with (4) USA Slimpaq T5 24W 6700k Daylight Plant Grow Bulbs

4*24/29= 3.3 WPG

Also another advantage in gathering this arrangement of two units it allows me to stagger the lights on and off. Does this setup sound good or is there another combination that may be better suited to my aquarium needs.

 

[jesseoneill]

That sounds good, but could you provide links to the fixtures you found? The only 24" Aqualight T5 fixtures I can find are 14W.

 

[PortWash]

That sounds good, but could you provide links to the fixtures you found? The only 24" Aqualight T5 fixtures I can find are 14W.

http/store.seacorals.net/cuusaslt567d.html

 

[jesseoneill]

Can you show the fixtures? Fixture wattage and bulb wattage have to match, otherwise you could run into serious electrical problems.

 

[PortWash]

O well that is good to know. The fixture wattage is 28, the bulbs are 24w. So you are saying that wont work?

Coralife 24" T5 28w Double Linear Strip Light

Each double linear strip comes with a combination of bulbs made for either freshwater/reptile or marine use.
Bulb Mix: Tropical Colormax/6700k

http/store.seacorals.net/24aq28wt5dol.html

No where does it state the wattage of the stock bulbs. So i looked and found these.

Current USA T5 6700k Daylight Bulbs

Slimpaq T5 lamps provide the ideal light spectrum with higher lumen output than standard T8 & T12 lamps. Their high lumen-per-watt output ratio makes them the ideal choice for optimum energy efficiency in all aquatic applications. The slim 5/8" diameter allows them to be used areas where space is at a premium.

Using Current’s proprietary blend of Nichia Phospors, SlimPaq T5 lamps are available in both 10000K Daylight and 460nm Super Actinic. Excellent for using with our Nova T5 Retrofit systems, Slimpaq lamps can also be used in any standard T5 fluorescent fixture. Their high light output and efficient power will provide the light your organisms need without breaking your wallet in electricity costs. Bulb size 24w 24"

 

[jesseoneill]

That won't work. Looking around a bit shows that the fixture isn't even 28W on each tube. It's 28W total, or 14W in each tube. Here are the fixtures that the bulbs you found will work in, but that's only (2x24W)/29g=1.66wpg.

Check out this, this, or this. Those will all either give you 1x65W or 2x65W (overkill for a freshwater tank). They're power compact fluorescents, so they let you put more wattage in a smaller space. You can also browse around at A H Supply for more options.

 

[PortWash]

Great the links were greatly appreciated. The only problem with the 65w options are one isnt enough and the other is too much. However, I found a 20" that provides 96w.

20" Coralife Freshwater Aqualight
Double Linear Strip Compact Fluorescent Fixture
(96W Total)

The only concern that I would have is that it is shorter than my tank. would that cause an issue?

 

[jesseoneill]

The only problem with the lights being shorter than the tank is that the outside edges of the tank might not get as much light.

 

[PortWash]

The only problem with the lights being shorter than the tank is that the outside edges of the tank might not get as much light.

Good point and in further research I found that the actual bulb portion is considerably shorter than the fixture. So in my estimation a 36" 96w unit would be perfectly suited ashide from the fixture hanging over 6" on either side. Thanks for your help it has been greatly appreciated in a process that from the start seemed like a much easier process then it has turned out to be.