On the heavily planted 20g tank I have the same lights I used to use on my nano reef: a small Current USA 10K PC light.
A similar light is on the 30 X-High, but I think I got a 12 or 14K bulb last time I replaced to punch more light to the bottom on that one. It's an eBay knockoff brand PC light strip called Catfish Lighting and it's been pretty reliable.
On the Brackish tank with Figure 8s is just a new Aqueon hood with standard fluorescent daylight tube. Bought that entire setup when Jack's did their $1 per gallon tank sale a couple months ago.
And the 10g with the RedTail puffer is, laugh if you will, an old perfecto hood with two 25w incandescents because heck, buying hoods for all these small tanks was adding up, and I had it on a shelf in the basement for the past 10 years, no joke! Pack-Rattery rewarded