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has anyone here actually measured the PAR in their tank? if so, what brand/type of meter did you use?

one resistor can be connected to multiple LED's. The important part is that whatever current passes through the LED's also passes through the resistor (which is why the resistor has to be in SERIES, not PARALLEL to the LED's). the idea is that as the LED's warm up, their resistance lowers...

you can expect a 3.1 - 3.8V drop across an LED. if you connect them in series, you just add it up. in parallel all the circuit sees is the one voltage drop. You have to be cautious about this because the net resistance of a parallel circuit is a lot lower than if you only had 1 diode in it...

Found an article relating the wavelengths of light and the PAR used by the different types of Chlorophyll. In building an LED array, are there any opinions on the balance of 3W white LED's to put into the mix with the LED's in the PAR wavelengths? Any recommendations for how many 3W LED's...

jumping in on this one: how does the Watt per gallon "rule" apply to an array of LED's?

the mA rating on a power supply is the MAX rating. i.e.: you do not need to match the mA rating with the LED's, just make sure that the LED's, and support electronics do not exceed the rated value. I would recommend putting the series resistor in. LED's by their nature reduce their resistance...

on the topic of wave generators: instead of a switching valve to redirect water flow (as most systems seem to use for wave-making), does anyone have experience with variable-speed pumps used for this purpose?

that's a great idea. I had thought about linking to the weather info to simulate lighting effects, but hadn't even considered wave strength!

well, quick update since I think I'll be back in this forum a bit more in the next few months: the Mrs got pregnant, so I took a transfer from Oregon State to The Citadel (in Charleston, SC). and we had about a dozen tests to prove it It has been crazy-busy between schoolwork, Navy stuff...

Been a long time since I've checked in here. I have to admit that Electrical Engineering is a lot more challenging than I had anticipated, and it's really taken up ALL my time. Add that the size of the family has recently increased, and a few other factors and checking up on forums has been near...

I love that story. Here's another squirrel story on a non-reef forum I regular: Animal lovers, never fear. Squirrels can take care of themselves!

Well, I'm in Georgia now, been here for about 5 years now, but it's looking like at least another 5 before I can get back.

I've kinda been lurking in the shadows since the tear-down. I do spend a bit of time over in the off-topic forums now. Come Friday I'm off to Rhode Island for 6 weeks at the Naval Science Institute (affectionately referred to as knife and fork school). From there I'll be off to Oregon State...

I collected a few thousand cards from various sports when I was a kid. Now they are just sitting in a box somewhere in the attic. I probably should pull them out and see if any of them are worth anything these days.

http://www.youtube.com/watch?v=fQMlf-n1kgU

Good timing PEM. This last Sunday I covered this topic with my youth group. The lesson was centered toward James 4:14 "What is your life? You are a mist that appears for a little while and then vanishes."

Just calling me, Al? Not going to raise any? Well, here's another one for the gun lovers out there. http://www.youtube.com/watch?v=vjK_yFNIHHQ

saw this on a different forum, and figured it would be fun to start here. Just post your funny video find here. http://www.youtube.com/watch?v=qGKXoryGymA

Ummmm... What kind of cruise was this?