corals dying slowly

[alton]

Of all the SPS corals I have seen in freinds tanks they keep them towards the top of the tank with 250 watt MH min. One thing I missed on this post was how deep is your tank? I think Tim hit the nail on the head with the 250 14k to 150 20k, try changing to 10k in the 150DE.

[adamRS80]

After much thought I'm considering selling everything and taking a break for a while. Are some of you guys are interested in some light deprived corals? I hope it doesn't seem like I'm making a rash decision, I acutally typed up a long list of everything and my reasons for selling about a month ago and just decided to stick with it a little longer. I just don't think I can afford to do anything with the lights right now and so tonight I'll probably post it all for sale unless I have a change of heart and decide to keep on trucking. We'll see. Thanks for everybody's advice, I would have to say with the response I've gotten and what I know about my tank, the lack of light has to be causing this issue so hopefully some of you can take my precious corals and give them what they need.

[adamRS80]

Joshua, I sent you a PM

[Tim Marvin]

http://www.marinedepot.com/aquarium_lig ... sp?CartId=

I'd try these if you can't get them cheaper from Greg at 360 ReefFarms.

[GaryP]

hah, not up to spec Robert, better get cracking. ;) Water clarity plays a huuuuge role as well. I'm sitting at about mid 80's in Gary's rule of thumb and I'm actually reducing my photoperiod this week down to 7 hours a day for the halides.

Like I said, I'm at 91 with my VHOs on and they are out of operation right now. I think the 100 is a best of all worlds scenario. I figured out Gator's ratio and its almost 250 watts/sq. ft.

[NaCl_H2O]

3. The best rule of thumb I have seen for "how much" light you need for SPS and clams is that you need 100 watts/sq. ft.

Gary, measuring SqFt in which two directions, length x height?

Example: My 215g SPS is 72x24x29, so 72x29 = 14.5 SqFt = 1450 watts?
I have 3x400w 10Ks + 2x160w VHO Actinics = 1520w

So I am happy???????

[GaryP]

I am referring to the surface area of the water, so in your case that's 72 X 24" inches = 12 sq. ft.

1520 watts/12 sq. ft. = 126.6 watts/sq. ft.

Can a math major keep up with HS geometry and algebra? I didn't even have to use diffyQ.

[NaCl_H2O]

Actually, that would be 126.6667 watts/sq.ft. ;)

[matt]

Try changing the bulb to the XM (actually XDE, I guess) 10k and see if that helps. That's the cheapest and easiest thing to try first. Don't worry about actinic supplementation; that's mostly for color correction anyway. The 10k bulb will produce way more PAR (or PPFD, whatever you want to use as light intensity useful to photosynthesis) and that's what your corals need for health.

I still bet there's a water quality issue, though. Unless your new sand bed is heavily stocked with worms and other detrivores, probably it's not really functioning as a deep sand bed. When you put sensitive corals in this situation, subtle degrading of the water quality over time due to the new sand bed not being able to "keep up" with the bio-activity in a stocked tank can take place. I'm pretty sure that's what happened to my old tank after I moved it and replaced a lot of the sand bed, and eventually most of my corals died. It wasn't until I bought 100 bristleworms and all sorts of microverts from inland that the system turned around. In the old location, with a mature live sand bed that developed along with the corals in the tank, everything was healthy.

That's my theory, anyway. I have no proof for it, but it was really the best explanation.

[adamRS80]

Thanks Matt. I'm going to do something about the light, either replace the bulb with a 10k or get a 250w light and get back to where I was, and then I'll get to work on my sand bed.