[jsgates]

Overnight, one of my acropora corals has started to flake off and is almost all white! Checked my water paramaters:

SG: 1.026
PH: 8.2
ALK: 4 meq/
Nitrite: 0
Nitrate: 0
Ammonia: 0

CA: 350

Calcium was a little low, so added some of my Seachem Reef Complete CA. Going to raise it a little at a time to get it back in check. Strange thing is the other two acropora's are doing fine. The green encrusting Montipora I posted about earlier is still the same......still live, but still not green. The SPS corals are high in the tank with T5 VHO lighting. Water temp doesn't get above 82 degrees, and when I added the SPS, I added two more power heads to increase the flow over these corals. Strange thing about the problem acropora is that it has a direct flow from one of the powerheads going over it. Any suggestions for saving this coral. This stuff is not cheap!

[jimw369]

Originally Posted by jsgates

Overnight, one of my acropora corals has started to flake off and is almost all white! Checked my water paramaters:

SG: 1.026
PH: 8.2
ALK: 4 meq/
Nitrite: 0
Nitrate: 0
Ammonia: 0

CA: 350

Calcium was a little low, so added some of my Seachem Reef Complete CA. Going to raise it a little at a time to get it back in check. Strange thing is the other two acropora's are doing fine. The green encrusting Montipora I posted about earlier is still the same......still live, but still not green. The SPS corals are high in the tank with T5 VHO lighting. Water temp doesn't get above 82 degrees, and when I added the SPS, I added two more power heads to increase the flow over these corals. Strange thing about the problem acropora is that it has a direct flow from one of the powerheads going over it. Any suggestions for saving this coral. This stuff is not cheap!

If its completely white and all the flesh has stripped off it then its dead.

How long have you had them in the present tank? How did you acclimate if you aquired them recently? Did you ever see the polyps extend on this coral and do they extend to feed on the other acros? Is it close to any other corals? Keep in mind..not all acros are high light animals.

Direct flow might not be exactly what acros need. Random flow or more of a turbulence I think is better IMO.

No. This stuff aint cheap!

Sorry for your loss.

[jsgates]

Flesh is not completely gone, but there is not much left. Strange thing is, these corals have been in the tank for about 3-4 weeks now, and this one was looking the best of all 3 of them until the other day. Got them from LiveAquaria (Divers Den special). 3 acros for $60, so it's not as bad as it could be. I've had good experiences with Live aquaria until recently. No SPS that I have received from them has really done anything at all in my tank. I also lost two Blue Linkia Stars from the same shipment......which is a bit frustrating since I waited for the tank to mature to almost a year old (10 months) before adding these stars that feed on the rare film algae. Anyway, I'm also feeding DTs every other day and the highest maintenance coral I have is a flower tree coral, and it is thriving. As for acclimation, when the Acro came in, placed them in a lower area of the tank for several days before moving them to top of the tank.

[jimw369]

Did you float them, drip them, QT them, do a dip on them? If a dip what did you use?

Too bad about the stars. Stuff happens sometimes. Ive always had a good respect for livequaria and there operation. I have seen first hand pics of their set ups in the back rooms. Very impressive.

[Jason L]

check your mag? that is the key

[jimw369]

Originally Posted by Jason L

check your mag? that is the key

What does your Mg need to be for sps? Ive had sps RTN with my mg at 1360-1400

Its been my little experience with SPS that steady water params is crucial to their survival. I have 20 sps in my tank now, most 3-4"colonies and I cant keep on going cause I dont have the water volume to hold Ca and alk steady without a Ca reactor.

[Jason L]

the mag is what keeps all the other things in check. Mag should be 1500

[spanko]

sounds like RTN and it happens. That is why people say acropora are so hard to keep.

[jimw369]

Originally Posted by Jason L

the mag is what keeps all the other things in check. Mag should be 1500

Could you explain "in check"? Thanks.

[spanko]

Here is an except from an article by Randy Holmes Farley.

Magnesium

Magnesium's primary importance is its interaction with the calcium and alkalinity balance in reef aquaria. Seawater and reef aquarium water are always supersaturated with calcium carbonate. That is, the solution's calcium and carbonate levels exceed the amount that the water can hold at equilibrium. How can that be? Magnesium is a big part of the answer. Whenever calcium carbonate begins to precipitate, magnesium binds to the growing surface of the calcium carbonate crystals. The magnesium effectively clogs the crystals' surface so that they no longer look like calcium carbonate, making them unable to attract more calcium and carbonate, so the precipitation stops. Without the magnesium, the abiotic (nonbiological) precipitation of calcium carbonate would likely increase enough to prohibit the maintenance of calcium and alkalinity at natural levels.

For this reason, I suggest targeting the natural seawater concentration of magnesium: ~1285 ppm. For practical purposes, 1250-1350 ppm is fine, and levels slightly outside that range (1200-1400 ppm) are also likely acceptable. I would not suggest raising magnesium by more than 100 ppm per day, in case the magnesium supplement contains impurities. If you need to raise it by several hundred ppm, spreading the addition over several days will allow you to more accurately reach the target concentration, and might possibly allow the aquarium to handle any impurities that the supplement contains.

An aquarium's corals and coralline algae can deplete magnesium by incorporating it into their growing calcium carbonate skeletons. Many methods of supplementing calcium and alkalinity may not deliver enough magnesium to maintain it at a normal level. Settled limewater (kalkwasser), in particular, is quite deficient in magnesium. Consequently, magnesium should be measured occasionally, particularly if the aquarium's calcium and alkalinity levels seem difficult to maintain. Aquaria with excessive abiotic precipitation of calcium carbonate on objects such as heaters and pumps might suffer from low magnesium levels (along with high pH, calcium, and alkalinity).

Here is the full article.
Reef Aquarium Water Parameters by Randy Holmes-Farley - Reefkeeping.com