Lighting/wattage & moonlights....

[cincinnati]

Hi All,

another question.... as I am so confused.... :dk::wb:

I have been doing a little bit of research about lighting and the wattages in preference for live plant/fish.

So, I found that with gallons... it is preferable to have 2-5 watts/gallon, and with litres its 1 watt/3 litres....

Working out my tanks....

watts/gallon:

3ft tank = 1.3w/gal with a 30W T8

5ft tank = 1.8w/gal with a 36W T8

8ft tank = 3.95w/gal with 2x30W T8 (not set up yet)


watts/litre:

3ft tank/150L = 50W

5ft tank/250L = 83W

8ft tank/905L = 301W

So according to the gallons formula, I have plenty of wattage for my 8ft tank, but not according to watts/litre.

My 3ft and 5ft tank all grow plants really well... I have java fern, riccia and 3 others that I don't know what they are as I got them with my tank, maybe one is java or peacok moss... not sure.

I wanted to increase the wattage to spur some growth on in the 5ft as I'm nicking some of the reproduced plants for the 8ft tank.... (when I get time to set the thing up!) and seeing as tho the watt/gallon calculation comes just under 2; I thought I'd put one of the 30W lights for the 8ft tank on the 5ft to increase the light a little.... but now the gallons calculation make the numbers drop to 1 watt/gal????!!!!!

I am worried now that the 2x 30W lights/reflectors I got for the 8x2x2 tank will not be suitable....????

Does anyone have any idea or a better formula to use???

Also do people use moonlights on their tanks? Any pros/cons???

thanx in advance!
C

 

[Lornek8]

Um, the calculations don't look correct for the 8ft tank unless I am missing something. 8x2x2 tank is about 225 gallon size which equates to about 900L or so. 2x30W t8 only equals 60watts or about 0.26 watts/gallon. Think you did the calculation upside down (225gallons/60w = 3.75gallons/watt not watts/gallon).

2watts per gallon is about sufficient to grow mosses & other low light plants. You probably need more if you're looking to grow some medium or high light plants. However, once you start to get into the higher light levels you really are going to need CO2 or some other carbon supplmentation to get optimum growth out of the plants. Otherwise, especially in highly stocked tanks, you'll simply end up with more algae.

 

[cincinnati]

Thanks for that!!!! I sux at Maths!!!! :wb::wb:

So does that mean I need 300W for low-med lighting in my 8x2x2??? Looks like I'm on the search for lights now!

Cheers,
C

 

[Lornek8]

Thanks for that!!!! I sux at Maths!!!! :wb::wb:

So does that mean I need 300W for low-med lighting in my 8x2x2??? Looks like I'm on the search for lights now!

Cheers,
C

Probably more like 450 watts.

 

[SmithRC]

I'd stick with low light plants in a tank that size... by te time you've got the lights right the CO2 and ferts would be rediculous.