OK, thanks folks! So, assuming I run the circuit on 12v; I have 2 more dilemmas: the 3 blue LEDs could be in series with a single ~150 ohm resistor but the two "flickering" LEDs should be run in parallel independently so the flicker doesn't affect the other LEDs correct? Also, how do I figure out the resistance values for the LDR under different lighting conditions (I assume this will affect what resister I put in place of the 100k resistor that is there)?

 

When manufacturing, you may not be able to make Vf of the LEDs all the same. if they come from the same wafer they are closer.
Vf you can measure. The diode function on your DVM might work. A voltage source with a resistor at about 20 mA would work too.
Measure the voltage across the LED which is Vf.

Bin your leds in say +-5% bins from Vf(min) and Vf(max) They should then be the same brightness when in series.

You always have tolerances to deal with.

PS: I kinda wanted you to see that the supply voltage wasn't high enough without explicitly saying so. I wanted you to look at the datasheets too without explictly saying so.

 

I have 2 more dilemmas: the 3 blue LEDs could be in series with a single ~150 ohm resistor but the two "flickering" LEDs should be run in parallel independently so the flicker doesn't affect the other LEDs correct?

Without knowing more about the flickering LEDs, it's difficult to say. I have a blinking LED that will cause other LEDs in series with it to blink.

Also, how do I figure out the resistance values for the LDR under different lighting conditions (I assume this will affect what resister I put in place of the 100k resistor that is there)?

If you want a crisp transition from off to on, you'd be better off replacing the LDR+transistor with a voltage comparator. Since many comparators will only sink half a dozen milliamps, you'd need a PNP transistor. You could do it with an NPN transistor, but the comparator pull-up resistor would limit current in the same way that the 100k resistor in your current circuit does.

 

I’m most familiar with the LEDs referred to in dl324’s post. So you’d have to wire both of them with a resistor in parallel with each other.

In the case where you don’t mind both LEDs blinking in unison, I’ve seen circuits with one blinking led in series with a non-blinking led. Ideally, they’d have the same current requirement.

 

Thanks folks! I will breadboard this whole circuit out when I get home. Your input and knowledge have been extremely helpful, thank you for taking the time to help!

 

If you still want to stick with 3.3V supply, all you need is an additional transistor (PNP)

I recommend you download falstad circuit simulator, a great basic tool to learn electronic