Understanding my lights?

A while ago (a couple of years), when I couldn't keep plants alive, I researched and learnt that I needed more light for my tank (that was the prevailing wisdom at the time - which has since changed) ...eventually I got around to purchasing new lights, which I have only just started using in the last 3 weeks or so.

My research at the time, when I was wondering what to purchase, was all saying T5 was the way to go, so I went to LFS and ordered a new lighting system... but the truth is... I really don't understand what I have or how to use it effectively.

My tank is 4 ft ~45 gallons.

I purchased a T5 system that can hold four globes. When it arrived it had two 54 watt white 10,000K HO globes and two 54w HO blue? globes. Two of the globes are controlled with one switch and two are controlled with another. A total of 216 watts.

When I turn on all globes the tank looks amazing! So many oxygen bubbles! Fish have behaved in a much less timid way... as I did a bit more research and began to run into problems because of my "high light" set up I have learnt (from here) that I have WAY too much light for my little tank.

So I have started leaving two of the globes off and reducing my photoperiod. Still lots of oxygen bubbles. The bulbs that I do turn on, one is white the other blue.

However do I still have too much light? My calculations give me 2.4 wpg - but that could be completely wrong... What are those blue bulbs for anyway? Should I just use the white ones.... aargh such a NOOB jumping in the deep end with no clue.

If you can give me ANY clue I will be grateful. I became an instant subscriber here because it is one of only a few places where you can find good, solid information.

Thanks in advance.

 

Thanks for your input.

I am realising more and more how much I really didn't know and still do not know. And how easily the internet can lead you astray unless you keep researching... 10 people, 10 different opinions... and you are left none the wiser.

It doesn't seem that I will be getting a PAR meter anytime soon, so I will swap over the actinic bulb with the white and see how it goes. I have the suspicion that with T5HO globes I can really reduce the photoperiod as they are more efficient I probably have a higher light level in the tank than WPG rule would suggest ... but I will have to stay with WPG estimation at the moment and just keep an eye on the plants. As long as I keep the other nutrients non-limiting everything should be manageable.

Everything you learn to keep fish needs to be almost completely relearnt when you start with planted tanks... dosing phosphates was a completely new concept to me, but it sure took care of that green spot algae that I had to remove every week...