400 gallon project

[untamed]

Originally Posted by fkshiu

That's an important observation made possible by the little PAR meter. I'm glad that the time/money/effort that went into its purchase has paid off for someone in a tangible way.

The bulbs were scheduled to change out regardless, but the PAR meter gave me some hard data concerning how bad they had become.

I gave up attempting to accurate measure the PAR at various tank depths. I simply measured the bulbs at surface level with the lights a set height above that. That's about 8" or so and I can easily measure a 25% difference between my old and new bulbs (same bulb type) At depth, this seemed to translate into about 1/2 the PAR, but these readings were pretty sketchy.

Yes...now to follow up with that device every now and then to find out how quickly the bulbs fall off. Clearly, my original plan of annual replacement isn't going to work. Maintenance cost just went up!