400 gallon project

[fkshiu]

Originally Posted by untamed

7) I replaced the light bulbs. I measured that my existing bulbs were putting out 25% less PAR than the new bulbs.
8) Coral immediately began to look better. I had not realized how much coral colour had gone away.

So..in the end I now believe that my ONLY problem was that my bulbs were old. Everything else was a spin off effect from there. At this point, I believe the corals are healing. Unfortunately, some have suffered such damage that it will probably take months to recover completely. I probably lost 2 or 3 corals completely.

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.

[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!