Coral Color

[johnrt]

Hi:

I have been reading about carbon dosing and Ultra Low Nutrient systems (ULN). The proponents of ULNs are probably using 'nutrients' in a different sense than is used here, but their thinking is that these conditions tend to enhance colors, particularly in SPS corals.

ATS tanks would seem to be at the other end of the spectrum, nutrient wise (plenty of food!). For people who have been running ATSs for some time: what is your experience in changes in coral color and growth rate, before and after? Any differences between SPSs, zoos, mushrooms, monties?

Are Xinia still the only corals that do not seem to like ATSs?

Thank you:

John T

[rainerfeyer]

Since utilizing the ATS and discontinuing the PS, I have seen nothing other than immense growth spurt and color improvement in the SPS and LPS.

Unfortunately, the Xenia types do not do well; I believe they need a high Nitrate/ phosphate environment but do not know this for sure.

Rainer

[SantaMonica]

Nutrient = Nitrate and phosphate = bad.
Nutrition = Food = good.

ULNS strive for the same thing as scrubbers. Problem is, their systems require a skimmer, which also removes nutrition, so they get lower growth rates (although, good color).

Good color requires low nutrients. Growth requires food.

My digitata double in mass about every month, and I only have 150 halides.

[jgreen1025]

Correct me if I'm wrong, but I think the idea is that higher nutrients causes the symbiotic algaes in the tissues of the corals (zooxanthellae) to multiply excessively and mask the color of the coral. That's why scrubbers are great - they drive down the nutrient levels without removing the natural food items the corals need (in fact, scrubbers ADD to the natural food items).

But it's also why Xenia have a harder time in extremely low nutrient systems. It is believed that they feed on those nutrients through direct absorbtion across their tissues. (See this article (http://www.reefkeeping.com/issues/2004-02/ac/feature/index.php))

[SantaMonica]

Correct