Amount Of T5 Lighting For 15 Gallon

[phishyphil]

Plan

Will be creating my own T5 lighting hood and unit, however as I am a total Noob to all things of electrical nature and lighting especially, I am in need of some advice. Now I now this whole WPG rule is outdated and other factors determine successfull plant growth and inhibit algae.

My question is what would the right amount of light be over my tank.

The tank will be 2' x 1' x 1.5'

So from substrate to Tank surface it will be 18". The light unit will be positioned 6" above this. So a total of 2' from substrate to light.

I will be Running T5s and the balast I intend to use is a dual bulb with each being 24w (Total of 48w)

T5' Bulbs used will be 2 x 6500k daylight Bulbs Link Below

Link To T5 Bulbs

This will give me a WPG of 3.2wpg

Tank will be pressurised co2 and daily dosed with ferts, nutrient rich substrate.

Will this be okay?

 

[DrRob]

That's a lot of light. It's possible to get away with it, but you may struggle getting the fine balance right. The Watts per gallon rule was initially created for T12 bulbs, which aren't as efficient at throwing out light than the T5's, so basically they give more light per Watt.

If it were me doing it, I'd probably drop back down to 14W bulbs like these http/www.lampspecs.co.uk/Light-Bulbs-Tubes/860-and-865-Daylight_8 and I suspect you'll still find that it's a lot. You could of course work by shortening the photoperiod a lot, but it's still a lot of light to try to balance. I've done it successfully for a while (2x24W on a 30" tank), and it lasted and things grew like wildfire, until I went away for a weekend.....then algae city.

 

[phishyphil]

Yeah I thought the case. Want to have a HC carpet growing, and the T8 unit I have just won't cut it I feel. Need the high light there to keep the HC Low and compact. Ahh well, maybe Steveo's LED unit is the way to go!

 

[Ps3Steveo]

Equivalent of 2wpg would grow HC easily mate. More light more to go wrong and less room for error.