BigJoe123

Ive had my freshwater fish tank for over a month now and its cycle has just completed. I really want to get some good plants going and Im completely confused about lighting. Everything seems so expensive and I dont want to buy the wrong thing. My tank is 48x18x21 and to get 2 watts per gallon the only lights I can find are marketed as saltwater reef or coral lights (most with moon lighting and actinic lights). Does anyone know of any good name brands or even general information. Ive read about every article on aquarium lighting on the internet and it doesnt seem to help. How many watts do I really need. Is metal halide worth it? Could I use a saltwater light if I can find a used one cheap?

mathas

Are you a do-it-yourself kind of person, or would you prefer to buy a pre-made lighting fixture?

The reason for that is that there are too many variables involved to realistically say "if you have X gallons of water, you need Y watts of lighting". You would need to take into consideration tank dimensions, type of lighting (T5HO, compact fluorescent, MH, etc.), plants desired, and your plans for carbon and fertilization. Budget also plays a pretty pivotal role in lighting selection.

For starters, do you have any idea what plants you might want to use?

It certainly can be.

The fixture, yes; bulbs, probably not. Marine corals generally thrive on different wavelengths of light than do freshwater plants, so you would probably want to avoid any actinic or marine bulbs if you desire strong plant growth.

One thing to keep in mind, though, is that fixtures marketed for saltwater use are generally of a higher lighting intensity than those marketed for freshwater use... and the more lighting you provide freshwater plants, the more they will try to photosynthesize, which means an increased demand for carbon and fertilization.

So yes, a "saltwater light" can be used for freshwater with the appropriate bulbs, but it may end up making things more complicated.

BigJoe123

Ok I went out and bought a glo H.O. 2 x 54w light and kept my exisiting 40w N.O. light fixture on top of my tank. The bulbs are a 18k power-glo and a 6.7k life-glo (t5) and a standard N.O. 40w generic flouresent (t8?, the big one). Should this be enough on my 75 gal. tank for low to possibly mid level lighting?