changing brand of MH bulb affecting algae growth

[eaglesrx]

I know I've heard stories about aging bulbs affecting algae growth. However, I can't remember the correlation. I'm assuming aging bulbs increase algae growth?

In addition, I can't remember if changing brands of MH bulbs can affect algae growth (same wattage) (increase or decrease??). I'm assuming if changing to a different brand that is defective or provides potentially less PAR (same wattage), then algae growth can increase?

Any help would be great. I just want to confirm these two potential correlations before I go back to my radium bulbs.

Thanks!

[Alex T.]

Aside from the aging bulb theory, I recently had an unexplained hair algae outbreak. After going through my checks (water chemistry, feeding regimen, maintenance routine, increased water changes, changing out ro/di filters, decreased photoperiod) the only thing I can truly attribute the outbreak to is a change in lighting 4 months ago. My system has never shown any traces of nitrate or phosphate, and yet there it was. I started running some gfo as well.

The recent switch was from 10k 400 watt xm halides on Blueline E-ballasts to Radium 400 watt halides on Galaxy ballasts. Although the radiums on Galaxy ballasts are bright, I know the par that the 10k xm's were delivering was substantially higher.

This is really the only thing in my system that has changed. Since the switch, an stn event occurred in which 75% of my sps and one maxima clam have perished. I thought this was a flatworm problem at first, so I did a Flatworm Exit treatment and saw nothing. I really believe that switching lighting kelvins can play a major role in an algae outbreak, as well as an undue stress to my corals.

I honestly like the 10k brightness better, but made the switch to Radiums because of the long acclimation period any new fragments from fellow reefers/retailers who all used more blue looking bulbs.

[eaglesrx]

thanks for the input! I actually switched from 20k 150W radiums to 20K 150W XM bulbs on the exact same ballast. The radium's about the same as the 20K in terms of brightness to the naked eye, but it's tough to tell.

Any other thoughts?

[jimrawr]

I recently changed(about 10 days ago) from 2x250 14k pheonix bulbs to 1x400w reeflux 20k bulb. Right away I am seeing a small diatom bloom, and even worse I am seeing small bubbles starting to cover things during lights on, which look like Dinos..

I havent added a single thing to the tank in around a month and a half, so I am attributing it to the lights..