Catherine not sure if you covered this but what are the temp swings in your tank? When acclimating the corals to the light do you place the corals on the sand bed and slowly move them up into place where you want to place them?

OK 1 hour later and I'm caught up on your horror story. WOW this has been going on too long. I commend your efforts.

I'm not sure at this point I would trust your Nitrate monitor. With the algae issues you had it clearly indecated you had an issue. I'm wondering if there is just too much nutrients in the water. I think you have addresses alot of it by checking your TDS out of your RO/DI but what is still in your tank? I'm sorry I might have misses it but are you running Phosphate remover?
I know your running Carbon. Another think I read and wanted to share.
When cleaning your filter socks. I use baking soda it gets them really clean + if there is anything left it will just add alittle temporary ALK boost.

Looking at the pictures of the SPS it appears the biggest symptom of desater is the loss if the slime coat. I resently experienced this and found a combination of low Alk and high SG was the cause.

Sorry I know it's late in the game and I maybe repeating other comments.

J

I experience very little temp swing in the tank itself, throughout the day the tank runs at about 80.3ish, and the lowest it gets to is 79.7. When the MH turn off is when I see the dip below 80.

So here is how I receive and put SPS into my tank;
- float the bag for at least an hour to get a consistent internal temperature
- take SPS out of bag and let it slime up
- Do the TMPCC dip.
- Interceptor bath in a separate system/inspect for AEFW
- Frag into the system

I've tried acclimating them two ways; first just sliming them up and putting them straight into tank water, and the second is slowly acclimating them to the tank water. I find I have a better survival rate overall if I just slime them up then toss them in.

Placement and light acclimation depends on the frag and its previous home. Usually though I place them on the outskirts of the tank, not directly under the MH, and if they flourish there then I leave them, if not they slowly over time get moved towards the center of the tank and under the MH.

As for my test kits, I use both the meters and the chemical version at least once a month to ensure they both balance with each other. I've also had my water tested by two other sources, a store and another reefer. When this first started happening I thought maybe my kits were out or something had happened to them in the move and I replaced them all in December/January.

I used to run GFO when I had hair algae but since its gone I've stopped running it 24 hours a day. It also seems to make my clams happier.

I still run carbon 24/7, I replace it everytime I do a water change, so about every two weeks. Its run a phosban reactor.

I wash my filtersocks in hot water twice to three times. I've never tried the baking soda method. How do you do it? Just put it in with them? Or do you sprinkle it on and let it sit?

As of a few hours ago my dKH reads 10, but its on the cusp of being 11, and my sg is 1.025. Ca is 420, didn't test nitrite or ammonia, and nitrate comes up as undetectable on the meter. I will do a chemical nitrate test to see what happens.

Actually this is the first time anyone, on either board, has mentioned the slime coat! Its progress!

Today when I look at the frags one is still doing fine, good polyp extension. The one that seems immune is a digi with neon green polyps. The cap is looking bleached and has lost some color, and shows 0 polyp extension. The third is a stag and I've moved it out of the direct path of the light after I saw some bleaching on the coralites. The final one is doing nothing, it never really showed any polyp extension when it went into my system, and it has a few tips which may be coloring up, or may be bleaching its hard to tell at this point since the tips are faintly colored. If I didn't know better I would say its growth.

Not everyone wants to sift through the 23 (or so) pages of it though! Yeesh! I skimmed the 23 pages in about 10 minutes, and that was bad enough. :lol:

Have you tried any of these recommendations yet? Any changes?

Actually I'm still gathering data, its only been a day and half since I posted this. I am also still waiting on the delivery of my ORP monitor so I can't do anything until I've decided on a course of action.

Sounds like some of your sps are doing better. I'm no expert and I might be completely off but if things go downhill again I would suggest looking at your lights. Having seen your tank first hand I can say that it allot of lighting for a small tank. If you have an extra halide, or oven a different reflector (one not so good, so pretty much a downgrade) and see what happens. All your other levels and everything seem good so I would investigate the light a bit more.

Maybe I will swap out the reflector for a week, and try that. I only like to try one thing at once though. I guess though doing a reflector swap would give me a week or two in the very least to search out other ideas.

Jason can we discuss the lack of slime a bit more? Are there any other causes?

You should be able to cut PAR without having to change out hardware. Maybe a bit of gauze over a few sections of the reflector?

C,
I have seen the slime coat lose in my own tank. It has occurred with High SG and again with a fist spike of ALK. Basically the coral starts to look dull and there is no polyp extension. I believe it is a recoverable situation as 4 or 5 of my corals have recovered. But others did not. The next stage tends to be tissue lose and growth of algae on the skeleton.
Unlike RTN or even STN the lack of a slime coat (IMO) indicates a slow progression of a stressed coral with 2 outcomes a return to health or death.
I don't think this helps too much with the diagnosis of what is causing it but instead leave us right where we are.
What can be stressing your corals.
We have ruled out measurable water parameters
We have ruled out chemical or other coral attack (usually kills small sections of coral)
We haven't ruled out silicone leaching
We haven't ruled out unmeasurable water parameters (contamination) but you would think it would effect everything

Light sure is a possibility. your running a 150W DE right? what is the UV is not being stopped? That would do it

J

I have another reflector on hand so its a cheap change.

If I were to add gauze or screening over the reflector what should I do? Cover it all, or just parts of it at time?

If its light burn the I assume in a week or two I will start to see darkening of the SPS. Maybe brown out, or just a change in coloration.