Fluorescent Wiring Question

You know the wires that come out of Duel Bulb Ballasts?

In this arrangement:

2 Red
2 Blue
4 Yellow

Well, I am making a ballast box so it is safe from water, and to wire those wires to a hood, I wanted to know if i could merge, for instance, the 2 red wires into 1 red wire, and at the hood, split them again.

Also, If I am using 2 identical ballasts, could I merge, for instance, all 4 red wires then split them again?

K, I set it up, so apparently it works. Here is a diagram (It is in an old Macintosh case)



The lights will be 4 20w 24".

I tested with one, and it was fairly dim.... when i use power from both ballasts it got about twice as bright. I am using audio cable, so maybe it doesnt transfer power as well?

K this is fudged...

I am using 2 Rapid Start T12 40 watt dual bulb ballasts.

I want to have them run 4 20 watt bulbs (2 for each ballast)

Obviously, these bulbs run 20 watts less than what the ballasts are designed for.

I tested my ballast set up on a 15 watt tube, and it gave me snakes and wasnt bright at all, quite dim (medium purple).

Once I put in an old 20 watt that has given off a stable purple on any hood, it had no snakes, and seemed to run more stable.

Would INCREASING a bulbs wattage change the way it acts, and possibly make it brighter? I would assume that 40 watts of power going to a 15 watt bulb would make it super bright, not dim... since on its standard ballast (For a 15 watt) it is quite bright...

Anyone? I have been waiting almost a day for help and no one has replied...