SPS Corals Struggling

[jharding08]

I've had some recent issues with some of my stony corals starting to die off.

My biggest colonies, Tri Color Valida, Sunset Millipora and Green Slimer have all started to die from the inside out and bottom up.

Valida (looks worse now. More brown tips) You can see the green slimer on the left. It bleached out on just the top half of the branch and at the base of the colony.


Sunset Millipora (More burnt tips and necrosis from inside out)


I've had more burnt tips on other staghorns and bleaching out from the base up on SPS frags. I have a huge white burnout spot on the side of my chalice as well

Euphyllia, Seriatopora, mint pavona, maze brains, favia all looks fine still.

Montipora is losing color

I had a phosphate outbreak about 4 months ago and put GFO online. I got PO4 and NO3 to zero, but realized I had low Calcium (330) with alk at 9.8 and mg at 1500.

I dosed 1 cup of calcium solution which gave me 20 ppm at a time. Did this over a couple days to get back to 420

Alk has dropped to 9.3.

I also noticed that my RODI unit had TDS of 006 IN and 012 OUT of the DI stage. I ordered all new filters and RO membranes so hopefully that will help.

I am running 1 cup of ROX 0.8 GAC in a TLF150 in reverse flow mode to help with any contamination.

I use Red Sea Coral Pro salt. I havent tested this last batch, but it seems like all the large colony issues have happened since I bought this batch of salt.

My latest water parameters as of 3/6 (before weekly water change) were:
CA-430
Alk - 9.3
MG - 1450
NO3 - 2
PO4 - .03

I am trying to get my alk down to the 7-8 range as the burnt tips might be because of high alk. Should I do this slowly, but turning down the alk doser a little at time, or can I turn it off, get to my number and then maintain from there?

[diesel6353]

It may sound weird but I've read about similar issues from the stuff that's in the salt settling in the bucket. I usually roll my salt bucket along the floor before mixing.

[Sapelo]

What are you running for lights? It's my understanding that sps are more likely to bleach in higher ALK although to be honest 1. Your Alk doesn't seem all that high and 2. Your photos sort of look more like STN to me...

[jharding08]

I am running LEDs, Blue and Mixed at 90% max and whites at 45% max. I've had them at the same levels even when these corals were thriving.

Could it be the TDS in the RODI water? Or pests that cause STN?

[Vdubin00]

What is STN ?? Sorry I'm a lil new ,, and what kind of lights do you have and how long you had them ?

[jharding08]

They are Rapid LED Onyx lights hooked up to an Apex. They are about 3 years old

[jharding08]

STN is Slow Tissue Necrosis

[Vdubin00]

Ok thanks !

[jharding08]

Any other things I should be trying?

[danrobberg]

In the past I have had issues when dropping phosphates too fast.

[serbusfish]

I think you need a lower KH when you have lower nutrients, around 8 - 8.5 or you will get burnt tips as you have.

[jharding08]

Originally Posted by serbusfish

I think you need a lower KH when you have lower nutrients, around 8 - 8.5 or you will get burnt tips as you have.

Should I lower it slow by narrowing the dosing window or just turn the doser off until I get to my desired dKH, then adjust the dosing window. I need to drop at least 1 dKH

[jharding08]

I think I am just going to frag off what I can from the sunset millipora and then see if any of those make it. The main colony is just dying from the inside out. The valida might have a chance if lower alk will stop the burnt tips.

[jharding08]

Fragged off all of the sunset milli and put it around the display and frag tank to see if any of them catch on.

I did a water change on sunday and then tested the alk and calcium and the alk was at 10 and calcium at 450. If, in a low nutrient system, alk under 8 is best, why does red sea have a salt mix that has alk at 12? Is IO lower in alk?

Should I just turn off my alk dosing if I am getting 12 from Coral Pro salt and am at 10 after a water change anyway...and do a WC every week?

Or I was thinking of going to just plain old Instant Ocean...and supplementing 2 part.

[Reel North]

Io is lower. I try to keep mine between 8 and 8.5. Calcium at 450. Mag 1300-1400. If I'm not in that range corals suffer.

[jharding08]

So its either dont dose alk with Red Sea coral pro or use IO and dose to reach NSW values

[Reel North]

I'd use io and dose. I have a calcium reactor and use kalk in my top off.

I have no idea why they make a salt with 12 dkh. Stop doing alk till it drops down to maybe 8.3-8.5. Corals should recover.

[jharding08]

If I get my alk to 8.3-8.5,then do another water change with 12 alk, wont it rise again? then if I dont dose any it drops back down by the time for another water change.

To me, it makes more sense to do water changes with salt that replenishes to levels where you want your tank, not above. What am I missing?

[Reel North]

You need to change salts. This one is killing your stuff! Every guy around me that gets alk over 9 kills the sps. You need to let it all drop. Turn off the dosing and let it fall. Calcium drops much slower. Your alk will drop fairly quickly if you have consumers in the tank. Test each day at the same time. The amount it drops daily is your usage. Switch to io once the alk drops, and try for 8-8.5. Difference is amazing.

[jharding08]

I saw Alk in io is 11 where in coral pro it's 12.5.

[Reel North]

Beats me. I use io. I do 50g wc 2x a month, and dose kalk. Stays at 8.3