Help me save this coral

[adamc1303]

I got this coral like 2 months ago. It was doing well at first. But for the last 4 weeks it got this white spot that seems to be spreading.
Water
SG 1026
Calcium 420
Ammonia 0
Nitrate 0
Nitrite 0
PH 8.4
My water parameters have been good for 2 years now, but every now and then I will loose a coral. In the summer I had some temp fluctuation which killed a brain coral that I had. My only neglegence is that I should be performing water changes every 2 weeks but I usually go about 4 weeks. I also notice that my corals loos their vibrant colors after a while. They still have colors but they are a bit bleached out.
The first pic of the coral is when I got it about 2 months ago, the second pic was taken today.
Please Advise
Thanks
Adam

 

[viper_930]

What kind of lights do you have?
How high up is it placed?
My first thought was that it's getting too much light and starting to bleach. Chalices don't need a whole lot of light and IME many prefer to be nearer to the bottom of the tank.
Have you tested alkalinity?

 

[david24]

What are your lights and what's the size of your tank?

 

[adamc1303]

I have a 90 gallon with 2 x 250W MH and 2 x 2 110W VHO. 720W total!

 

[bonebrake]

What is your alkalinity and magnesium?
What salt mix do you use?
What do you dose in you tank? How much and how often?
:joy:

 

[adamc1303]

I dose the Bionic 2 prt suppliment. The first is for the PH and the 2nd is for Calcium. I never checked Magnisium although I do beleive I have a test kit for it. I use the coralife salt mix, always have and never mixed.

 

[bang guy]

B-Ionic part 1 is for Alkalinity, not PH maintenance. It's important to understand why. For now, you need to check you ALK, this is the single most important parameter for coral growth.
The coral shown isn't that bad off. I wonder if it just needs a litle bit more waterflow.

 

[adamc1303]

I doublt it flow since I have allot of flow. I have my return which is 600 GPH then 2 Maxi Jets that put out about 290 each and a rio that does 700GPH, 1880 GPH in a 90 gallon. That coral is also in a high flow area. Could it be that my lights are to strong?

 

[adamc1303]

B-Ionic part 1 is for Alkalinity, not PH maintenance. /QUOTE]
What is the difference between PH and Alkalinity? I use to use buffer every now and then befor eI had a reef. for the past year since I have been using B- Ionic I never needed to use buffer the PH has always been stable.

 

[ci11337]

It might be that your lights are to strong nd are causeing it to bleach.

 

[bang guy]

Originally Posted by Bang Guy
B-Ionic part 1 is for Alkalinity, not PH maintenance. /QUOTE]
What is the difference between PH and Alkalinity? I use to use buffer every now and then befor eI had a reef. for the past year since I have been using B- Ionic I never needed to use buffer the PH has always been stable.
"Buffer" is a marketing term. The correct term is "Alkalinity Additive". Alkalinity is the resistence strength to PH changes (for hobby purposes). It is hopefully mostly made up of Carbonate or Bicarbonate. Carbonate is the second part of Calcium carbonate. Without it corals cannot build skeleton.
Low PH is not caused by low Alkalinity. Using an Alkalinity additive to raise or maintain PH is just like using icewater to cure a fever. It will mask the symptom but it will do nothing to eliminate the cause.

 

[sebae09]

i dont think anyone could say it better bang guy

 

[adamc1303]

I only used buffer because my tap water would have low ph, so while mixing it with salt I would add buffer. Once it was in the tank I never had an issue.

 

[bang guy]

It's a really bad idea to add buffer when mixing saltwater.