What to do?

[SanDiegoreefer]

I introduced live rock into my first tank about 11 days ago. I've been running my lights about 6 hrs/day. The rock is turning a bit white. Is that bad? Also, at this point is there anything else I should be doing besides waiting?

[Shiandy]

I would monitor your Nitrite & Ammonia levels, so you can tell when your system has finished cycling, mine only took about a week, but many systems vary.

[sir_dudeguy]

the rock is turning white because all the coraline (can be green, purples, reds, orange, many colors) algae is bleaching. Check your calcium and mag levels to see where they're at. Thats what makes coraline grow. It can also grow without any light, but sometimes if you got really really strong lights, it wont grow as good. Whats your light sitiation?

[SanDiegoreefer]

I have a 36" Coralife Lunar Aqualight 53404. It has 96 watt 10,000K and 96 watt True Actinic 03 Blue square pin base compact fluorescent lamps and two 3/4 watt Lunar Blue-Moon-Glow LED lamps

Also, is it okay to turn on the lamps at the same time or should I turn on the actinic before and leave on after the 10,000k?

[Shiandy]

I'd have them on seperate timers, I find plunging the fish into total darkness can spook them, so having the Actinic come on 1st, and off last would be a good idea. You might also want to increase your photo period to 10-12hrs, 6hrs is a little on the low side.

[SanDiegoreefer]

Someone advised 5-6hrs at first to avoid algae bloom. Is that incorrect?

[Shiandy]

I don't believe increasing the photo period would have any effect on a algae bloom, high levels of nutrients will however.

Perhaps others could comment on this ?

[fsn77]

Actually, coralline algae does need some degree of light to grow. It is algae and does require some light to perform photosynthesis. It's growth can be limited by very intense light. It might survive without light for a period of time, but I wouldn't say it's growing. In our sump that receives no light, there is no coralline algae on any of the rock, glass, or equipment despite the rock and glass being covered with it in the main tank and refugium.

Keep an eye on your calcium, alkalinity, and magnesium levels. Maintaining those at the proper level will help the coralline grow and spread. Weekly water changes have been enough to keep magnesium levels in line for our system, but I need to regularly add calcium and alkalinity buffer.

If there's excess nutrients in your tank, increasing your photoperiod on the daylight bulbs (10000 K) could cause unwanted algae to grow. I've seen it recommended that while the tank is cycling it's better to run only the actinic lighting. I chose to run both the daylight and actinic bulbs and didn't have any unwanted algae problems. Opinions and results vary.

I have the actinics come on 2 hours before the daylight bulbs on our tank, and stay on 2 hours after the daylight bulbs turn off. Some people only go 30 minutes before and after, others an hour. I started having it at an hour, but like it better with 2 hours of actinics before and after.

[sir_dudeguy]

Actually, coralline algae does need some degree of light to grow

i dont agree w/that. Theres a fair few people who post here that they've cooked their rock to get rid of all other life forms (liek corals and stuff) in pitch black and they take it out to find more coraline. And i myself have rock in my sump which gets no light at all (no fuge in there) and coraline is caked on the glass in there. So i vote that it does not need light to grow. It does help tho, theres no doubt about it. I'm sure that if i had just one of those little coralife mini pc's over the fuge, it'd be way more coraline, but there is a good bit of it growing.

[fsn77]

Considering that coralline algae has been found at depths greater than 250 m (http://www.icess.ucsb.edu/~stephane/Payri_et_al_2001_H.o.pdf) and under the ice in the Antartic (http://www.hu.mtu.edu/~mmcooper/old homepage/classes/biome.html), there is no question it can grow under incredibly low light conditions. In cases where it's grown on rock that's being cooked, or even in your sump, I'm skeptical that either was / is in complete darkness (especially your sump, but I doubt you're striving for complete darkness). There's likely some amount of ambient light and what's growing are ones adapted to very low light levels. It would seem that I don't have those particularly adapted forms in my system since there isn't any coralline growing in my sump.

Variety is the spice of life... looks like my tank could use some more flavor. ;)