SPS newly question

[Treebeard]

...newby, that's newby question! Thanks auto spell correct.
I have 90 gallon tank, coming up to its 4 birthday and recently replaced my T5s with a new 48" Sunbrite led fixture and decided to try some SPS. I have an acro and monti sitting about 10" from the surface and the lights are 5" from the water. Should I be running the lights at 100% for a few hours each day or is that too much? I have had the colonies for about 2 weeks but the acro seems to be bleaching out a little at the tips. The parameters are all good except the nitrates were running between 15-20 ppm depending which test kit you believed.

[reefwars]

i would run them lower and slowly ramp them up over time .

the bleaching could be because of the lights or many other reasons.


how long have you had both corals??

[reefwars]

with high nitrates i believe youd get some browning out not so much bleaching although it can happen. granted that these are fairly new and so are the lights i would be looking into that for sure

[Aquattro]

Parameters are all good isn't really enough. Give us the values, maybe we can add from there. Alk can affect tips, too much light, not enough light, too much PO4, etc...
As much detail as you can. Time in tank, flow, all water parameters in ppm, temp, bulb type, whatever else comes to mind.

[Treebeard]

pH: 8.1
Ammonia: 0
Nitrite: 0
Nitrate: ~17
Phos: 0
Ca: 440
kh: 6.4
Alk: 2.29

Two Phos reactors, one running carbon, the other rowa.
Vertex in 180 skimmer
Refuge and chaeto
MP 40, (adding a second on the weekend to try to get a gentler wave action)

Tank is 75F

Fishy friends include a green spotted boxfish, hippo tang, sailfin tang, royal gramma, anenome fish, lawn mower blenny, matted file fish and a leapord eel.

Approximately 70 lbs live rock.

Thanks!

[Treebeard]

I estimate the lights are running at 100% for around 3 hours per day.

[Aquattro]

If it were my tank, I'd do a water change big enough to cut the NO3 by 25% minimum. The PO4 is suspect with a NO3 reading that high. Alk is a bit on the low side, I'd raise that to over 3.00.
Lastly, I'd raise the temp to 78-79. I've found that the growth rate increases dramatically at 79 over 75, and without enough growth, you won't get the corals healing any damage quickly enough, so exposed tips could start growing algae, and downhill from there.
So even if you fix everything else, the corals are still in danger from the existing damage. Elevated PO4 will also slow growth, so double check that with a hanna if possible.

[Treebeard]

I do 20% water changes every two weeks. I suspect that I have been over feeding but it has not been an issue for my existing lps but since I added the SPS I have cut back on the grub.

Raising the temp is easy enough. I have been cooling the sump by running a fan across the surface because I thought the high temps were contributing to the film algae on the glass.

Perhaps I should make this weekends water change a big one?

[Aquattro]

If you can, I'd do a 50% change. That will impact the NO3. The temp will contribute to the film algae a bit, but it's there for mostly the same reasons as the brown is in the corals.
That should clear up a bit once the other issues are settled.

I feed quite heavily (I guess that's subjective ) and don't have issues, so more of a nutrient management process. A great skimmer helps. Maybe smaller more frequent feeding? Or, if you're really dumping it in, back it off a bit.

[Treebeard]

I definitely don't dump in the food, actually the reverse. I contribute the high nitrates from the eels appetite for frozen shrimp. Having some buyers regret over that purchase, especially after he took a huge chunk out of a coris wrasse and my neon goby dissappeared. Ever since I make sure he is well fed, every three days.