Lighting and Coraline Algae

[Jerome]

My reef is set up as a shelf and it's a SPS only tank it looks great except there is no coraline algae growing on the light side of the shelf. I thought I would wait and eventually the shelf where all the coral are growing will be over grown by the SPS which is happening.

The bottom of the shelf is red, puple orange, pink etc. with coraline algae. The top part is blasted by 2 175w 10k MX Metal Halides for 10.5 hour a day over a 50 gallon tank. So the top of the shelf is rock greyish, and the SPS love it.

So, here is my question if I slowly over time reduce the MHs to 6 hour a day (which is all the SPS really need) and still run my atincs 11 hours will more coraline algae grow? I know coraline gets "burned" by the MHs so does the amount of expose time have something to do with it? If the top of the shelf get exposed to less MH lights will more coraline algae grow.

 

[Witfull]

the 2 things that control growth are intensity and duration...for coraline,,i dont know the ratio...but since intensity is something you cant change, duration may play a role.

 

[Jerome]

What I was thinking but does any know what the ratio is?

Maybe someone who uses MH and has coraline algae growth could post bulb, wattage, color tempature and distance from the water surface that might help.

 

[Witfull]

another thing to is,,,i hate to say this,,,,salt. ive been an oceanic user with sporatic mixing of IO and kent. recently Sera Brand Salt, became available, and having heard good reviews, i gave it a shot. in 2 waterchanges, my coraline has dramatically increased. im not claiming anything here, but nothing other than salt has changed, except for increased bioload. (removed 1 sohal tang, added 2 bluethroat triggers and coral lyretail hog) and within one month a purple spot on the glass 1/4" has turned into 1" circle with scaling.

so, i dont think its any one thing when it comes to coraline. to some its the holy grail, to others its the devils growth.

i would like to know the secret myself!

 

[bullet_buddy]

What I was thinking but does any know what the ratio is?

Maybe someone who uses MH and has coraline algae growth could post bulb, wattage, color tempature and distance from the water surface that might help.

I use 2 400mh 10000k 15'' above the water .Salt is instant ocean salinity is 1.025 no additives just 1/3 water changes evey 2 weeks.But I've notice the coraline grow faster in high flow areas in my tank,Dont know if that's a factor just something I noticed.Actually I'm switching the bulbs to 12000k reeflux bulbs this weekend so I'll post in a few weeks if it makes a difference in growth or not.