So would 10K really grow faster in my case

[Covey]

Okay after alot money and work I for the most part have now settled in to the grow out phase of the tank. I did the right thing and 90% of my SPS are tank raised aquacultered corals frags.

I shopped around quite a bit and settled in with the 400W 20K XMs. The color is exactily what I want but I have a tank full of tiny frags. The growth is good but I have nothing to compare it to since this is the only MH bulb I've ever run.

My tank is BB, high flow, over skimmed, but I feed moderate amounts. The colors nutrient wise on the acro is where I want as well. Solid, bright with no brown. Basically what I am asking is could I switch to say XM or reeflux 10Ks and get faster growth or would I get caught in that low nutrient BB coral lighten trap. Basically were you have to keep lowering the photoperiod to keep the corals happy. I run my MH 7 1/2 hrs a day and would not be happy if I had to knock it down to 3.

I now I am trying to have my cake and eat it too but do you think I would get better growth or just a shorter photoperiod?

 

[kirstenk]

I have the same lights. I run Magnetic Ballasts. The Reflux does not have the PAR that the 20K do so I would think....slower growth. The 10K will give you faster growth but you will have a color shift, they will not be as pretty, and lowering the photoperiod will defeat the growth imo.

I would keep the 20K and slowly up your photoperiod to 11/12 hours.

 

[Norwood IND]

Agreed. If you downshift from 20k to 10k you will get a color shift as well that you may not like.

 

[Covey]

Good call on the PAR numbers KK. Gotta love kelvin ratings.
The xm vs the reeflux. The 20K Xm has 20% more par than the 10K reeflux.

 

[menard]

If U really like growth, go w/ SAKIS and for viewing , combine it VHO super actinics. Now U have both
My frag tanks lit w/ SAKIS only,hell they grow, I mean they grow!!:eek2: