There are a few things I wish I'd done differently, but most of them are pretty trivial:
1. I should have run the wires through the fixture. It would have been a pain in the neck to drill all the extra holes and thread the wire through, but I think it would have been worth it from an aesthetics perspective.
2. I would have used smaller screws. The 8-32s I used were overkill and I had to use nylon washers to make sure the wiring was insulated from the screws holding the LEDs down.
3. I don't think I would have bothered with making the fixture rockable. I didn't take the thickness of the square tube into account so I still have to slide the fixture back on the tank a little to open the lid.
4. I would have used a linear potentiometer for dimming. The audio pot I'm using adjusts on a logarithmic scale so I don't get any dimming except for the last 1/4 turn of the pot.
5. I'd make a few minor changes in the frame design. Nothing major, just flipping a few members around and adjusting a couple lengths for easier assembly and better adjustability.
6. I'd have ordered all the electrical components together to save money.
I had to turn the LEDs down to 2/3 power after the tank had a GSA breakout in less than two days at full power. I've got dry ferts on the way and I'm hoping to get a CO2 tank for my birthday in a couple weeks. After I've got that stuff, I'll try cranking up the lights and see what happens. Even at 2/3 power, I've got a whitish film on the glass.
The good news is the plants are doing very well. I pulled out all the anacharis and most of the guppy grass to make some room for different plants. fort384 sent me some glosso and some rotala wallichii that are growing well. The rotala is a poor shipper and came out of the box looking a little wilted, but it's perked up now and turning a nice pinkish-red. My asian ambulia pretty much died off under the T5 light, but it's coming back with the LEDs. My crypt lutea is developing some pinholes in the leaves which is a sign of potassium deficiency. I'm hoping that starting a fertilizer regimen will boost the growth of the plants.
I've been crazy busy this week with work and trying to get my wife's car back on the road. If I get a chance this weekend, I'll take some pictures of the tank if it's presentable.