QUOTE(PurpleUP @ Nov 21 2007, 02:25 AM)

So I've been thinking about corals lately (go figure) - the SPS variety - and I figure I'm still a couple of months out until I can add any to my tank. The soft corals in the tank right now are just ornamental place holders until the SPS take over. Can anyone tell me when my tank might have enough stability to add some nice acropora frags? Can I slowly add some now? Tank is just about 2mos old. Or should my live rock be covered with coralline first? Not really an SPS guy, but I'm tryin to become one. Advice?
I love the tank, and am particularly impressed with your old BC14 thread. That thing is absolutely gorgeous. I am especially intrigued by the pro-rapids sump setup. Seems like a really nice unit, and a great solution for smaller tanks. I'm a little sceptical about the protein skimmer that comes with it, however. Seems like it might be a tad underpowered. Regardless, for a tank as small as yours, I doubt it will matter much.
My tank has almost no new coralline growth and sustains SPS quite well. Coralline algaes don't usually do as well with brighter light, and really grow best in the presence of calcium gluconates, something SPSes really don't require. (If you want to grow crazy coralline, think lots of actinic lighting and use seachem reef calcium or some other product that contains calcium gluconate. Regardless, these are not things SPSes really need much of, so I wouldn't worry about that.
Judging from your tank pics, and the success of your BC14, I would say you are certainly meticulous and consistent enough in your maintenence routine to keep SPS without a problem. Here are some things to think about regarding SPS husbandry:
1: Stability. SPS are less tolerant of change than softies. Better to have less than ideal parameters that don't change much than parameters that fluctuate alot, but average closer to ideal, if you know what i mean. Especially focus on keeping your temp and salinity stable. These two are relatively easy to test for and control, and changes in temp and salinity that wouldn't even stress a softie visibly could really hurt some SPS corals. The ATO system that comes with your sump setup should help with that. Seems like a neat feature.
2: Calcium and Carbonates. You will find that as you add hard corals to your tank, especially SPS, your calcium and Alk demand will skyrocket. Don't underestimate this, especially in a small tank packed with SPS. I personally love the 2-part additives like B-ionic. Calcium reactors are better. Don't use kalkwasser unless you monitor your pH and magnesium levels. Heavy Kalk use tends to deplete Mg, and can easily send your pH through the roof in a small tank. However, it is a great way to keep your Ca+ and Alk levels up there if you understand the possible problems that can occur with misuse.
3: Nutrients. Nitrates and phosphates should be kept as low as is humanly possible. Some softies seem to like slightly elevated nutrient levels. Most SPS definitely do not. Skimming, water changes, and natural denitrification (algaes, DSB) are all very helpful.
4: Light. You seem to have plenty of light in your tank, imo. I would take into consideration that shallow-water SPS tend to get light that is less blue than deeper water softies in the wild. 10K bulbs tend to get faster growth in my experience vs. 20k bulbs. This doesn't mean they don't won't do fine under bluer light, they will, its just not what many of them get in the wild.
5: Allelopathy. Read about it. Its less of a concern for softie tanks, but once you start mixing hard and soft corals, it becomes an issue. Some SPSes will exhibit stunted growth, poor coloration, or even bleaching in the presence of certain compounds released by leathers, zoanthus, mushrooms, etc. Consider using activated carbon if you don't already, maybe even poly filters. Agressive skimming and Large frequent water changes help too. If you are planning on keeping all hard corals, it becomes almost a non-issue, as hard corals tend to deal with their turf wars in a more visible manner, i.e., by stinging the living crap out of each other. Mixed tanks are more difficult than dedicated softie tanks or dedicated SPS tanks.
6. Water flow. As i'm sure you already know, SPSes thrive in water current that would irritate or even kill softies.
7. Feeding. SPSes can do fine without eating directly, but they really thrive and show their best colors if you are feeding them regularly. I use cyclops-eeze and oyster eggs soaked in selcon, squirted into the branches of my SPS every other day. Feeding isn't strictly neccessary with most SPS, but a well fed animal is more forgiving of other sins than a hungry animal.
I'm sure you knew most of this already, but hell, it couldn't hurt to type it out here for everyone's benefit. I don't mean to make it sound hard to keep SPSes, it really isn't hard at all. I have been keeping SPS for 15 years, and many of them tolerate quite a bit of neglect and abuse. They just have slightly different needs than soft corals.
-Josh