New scape but a bit rusty......

[curefan]

Hi all,
Ive just finished my hardscape on a new layout, but am a bit unsure of how many of my 80w T5's i should use. First of all ill be planting Cuba, Monte Carlo, and Hemianthus Micranthemoides with co2 injection and adding dry ferts.
The tank is 5x2x2ft and 2 ft high with an Arcadia unit (4x 80w) about 5 inches above the water.

Note the bulbs are about 3yrs old....do the really need to be changed???
Also i will be putting clear perspex over the water surface to decrease evaporation.....will this block much light??? It seemed to work ok for me before.

Am I right saying it would be medium light from the chart below with 2 bulbs on (only an option to have 2 or 4 on), and 4 would be too high?
So 2 or 4 bulbs, and do i need to get new ones?
I saw the other par chart but not sure how to calculate my par so just used this one!!

Thanks in advance, Dave.

 

[James O]

Start low and work upwards. Don't forget that you can also adjust the period the lights are on for. For example, you could start with 2 bulbs on for 6hrs a day. Then you can lengthen the period and/or add the other two bulbs for a short period kind of like a high noon effect. Maybe 2hrs at first in the middle of your lighting period and then extend it out until your plants are happy and aren't having algae issues. Some cheap mechanical timers will take care of it all for you

 

[curefan]

...yeah, I have all the timers already from my last setup as i needed it for co2 ect. I grew Cuba before quiet well but that was with a different setup completely and may of been just lucky!!!
Really want to get the lighting right, as to plant this big tank will be expensive and i want to give the plants the best chance possible.
I know lots of people say co2 and flow are more important which I take onboard, but I just really wanna know am I in the ball park for sufficient light with 2 bulbs or 4, and again, do i need to get new ones?

 

[tim]

2 tubes as long as they are the length of the tank should be plenty to grow most plants and you have the option of the 4 to speed things up as long as you match co2/flow and maintenance with the plant growth. Replace the bulbs if it makes you happy, personally i replace mine if they blow/ don't work, it all depends how much energy you want invest in the tank.