Not Convinced of Light Intensity
 

I am beginning to wonder if there is a lot more to coral growth than light intensity. I purchase a few montipora frags from Perkys Pets a number of months ago. I had the frags under a Ushio 10K 400 watt and the growth has actually been dismal, recently switched to the Iwasaki 250 watt and growth has picked up.

What I find surprising is the same frags at Perkys pets have literally doubled or tripled in size for the same time period. The lighting they are using is 6500K 175 watt bulbs. Kinda surprisng.

My water parameters seem okay calcium is around 400-425 ppm, alk around 3.0 meql, don't have a test for nitrates or phosphates, but no out of control algae.

Not Convinced of Light Intensity
 

Bryan,

There is much more. IMO. Light is one part where water qualty, circulation and food are the others. Now for everone the amounts of each of these is different. There is no set formula to follow. There are guides then you have to do the fine tuning to get everything in the spot the corals need to grow and thrive.

Not Convinced of Light Intensity
 

With the light, you may have been superdosing your tank too much, thereby stressing out the life in your tank... its basically giving somebody a 75 proof shot of vodka, when 50 proof will get you there....

You didn't tell us how big your tank was, but Im suspecting you were dosing too much light, thereby 'freaking' things out

Not Convinced of Light Intensity
 

<font size="2" face="Verdana, Helvetica, sans-serif">Where he has gone from a 400W 10KK to a 250W 65KK I'd doubt he shocked his corals all that much. The PAR ratings are very similar for the two. If he was stressing his tank out they wouldn't show increased growth from the 10KK to the 65KK. If anything they would have decreased growth, possible bleaching and in the extreme RTN.

More likely there is something missing or differnet between his tank from the tanks he purchased the frags from.

FYI