Coral Problems, any thoughts/suggestions?

[daniella3d]

well, water of 30 to 40 ppm of nitrates and .25 of phosphates is anything but "too clean".

I don't think that would be the reason for RTN though, because my nitrates are quite high right now and phosphates around .15 but I have no problem with my SPS, even the delicate ones.

I suspect a mixt of things, probably water quality, the light, and probably stability is pushing your SPS on the limit of their endurance.

I would not keep any leather corals with SPS. They are not very compatible and migth trigger chimical war. I avoid leather corals all together.

I would lower the nitrates with dosing with NOPOX, and use GFO to lower the phosphates, plus I would make sure the parameters are very stable with dosing for KH and calcium with a dosing pump. Make sure the light is not too strong. This is a good factor for RTN when the light is blasting the corals and LED is very strong and corals need acclimation for it.

[asylumdown]

I've never seen carbonate hardness expressed in those units, what does that translate to in dKH or meq/l?

How are you maintaining your water water chemistry? Are you using an auto-doser, or are you dosing by hand? If you dose by hand, how often do you test, and how much do your parameters fluctuate week over week?

IME SPS corals have a very hard time dealing with large swings in carbonate hardness over time, it stresses them out to no end. They can adapt to a pretty wide range of parameters, but not to regular swings in those parameters. I never had any luck with SPS until I got a doser and was able to keep my numbers (especially carbonate hardness) steady over a period of weeks. If your levels are fluctuating and you have high nutrient levels, it might just be too much for SPS.

[props]

Nitrate and phosphate are a tad high imho but shouldn't be an issue to why you're losing croals. How do you introduce corals to the tank?? Why I ask is you could be burning them to death due to your water clarity. Start them from the bottom of your tank in high flow areas or decrease the time your main lights are on.

[Myka]

Originally Posted by Yorgi

Nitrate - 30-40
Phosphate - 0.25

As everyone else said, I think nitrate and phosphate are likely the leading problem. However, the two values you posted don't really compliment each other too well. I would expect phosphate to be much higher than it is with the 30-40 ppm nitrate, and it very well may be. I do notice though that you have a lot of (what was) dry rock in the tank which colonizes nitrifying bacteria quite quickly, but takes much longer to colonize denitrifying bacteria. Denitrifying (anaerobic) bacteria mainly convert nitrate to nitrogen gas so a lack of these bacteria would allow nitrate to build up unusually high compared to phosphate. The significant bioload you have introduced to the tank in a mere 10 months adds to the problem.

Do you have room in your sump to add some live rock there? If so, I would suggest you add some more live rock to the system. This will help a certain amount, but will not take care of the problem by itself. You will need to get more aggressive in your cleaning. You only mention one powerhead, for a mixed reef that size you should have at least 2 or 3 powerheads with a combined turnover of about 25-40x the volume of the display tank (so about 3750 to 6000 gph) minimum. SPS will prefer much, much more flow. How often do you do waterchanges? Do you have biological media anywhere (like bioballs or ceramic rings)?