Interesting find...help

dailydriven911 · Mar 25, 2007

So I recently bought a couple of sps frags a purple acro and a green slimer. They did great for about two weeks until I noticed the polyp extension receding on both of them and the tissue receding on the purple acro turning white near the base/middle and branches. So I tested my water like crazy noticed my nitrates at 20 ppm and po4 at .04 not the best for sps but I don't think they would look that bad so fast. So I tested alkalinity and ph both came in okay 3.5meq/l and ph 8.1 a little low but I corrected that over a couple of days raising the alk to 4.5 meq/l and ph to 8.3. I decided to watch my tank for awhile and noticed my six-line wrasse was picking at it constantly especially the purple acro. At least 10x in just a couple minutes

These are also the only two sps frags that it's picking on. I have a larger staghorn that looks fine and pink milli and a couple of cap frags that seem to be doing okay. I'm wondering if the fish is eating something off the frags that I can't see or actually attacking the coral itself. I can't see any type of flatworm or red bugs but I won't rule it out. Anybody ever hear of this happening?

-Jayson

kevinpo · Mar 25, 2007

Decaying tissue attracts a wide variety of micro organisms that the Sixline would find good to eat. It's very unlikely that the wrasse is eating the healthy coral tissue.

On a side note, I personally do not like to see alkalinity above the 3.5 meq/L for extended periods of time. Many corals do quite well at that level but there are some that prefer 2.5 - 3.5 meq/L range much better. 8.1 PH is quite acceptable especially for a morning reading.

Regards,
Kevin

dailydriven911 · Mar 26, 2007

Okay thanks for the help I'm new to keeping sps so I need all the help I can get! I will lower my alk to 3.5. I'm dosing c-balance daily but I'm wondering since my tank is small (25 gal) that there is a dip in alk each day between dosing. The tank has been up for a year now and is stable and I've kept both soft and lps corals and they have thrived. I can't wait to get my 75 up and running with all the necessary equip ie refugium, skimmer, calc reactor

Damsel13 · Mar 26, 2007

Kevinpo I am glad to hear 8.1 si ok

kevinpo · Mar 26, 2007

People who run a calcium reactor without Kalkwasser additions find their PH typically runs 7.8 - 7.9 (morning reading). I also experienced this for about 18 months until I added a Kalk reactor and refugium on a reverse photo period. I never noticed any ill effects.

The more your calcium, alkalinity, and magnesium rise toward saturation levels the harder it becomes to keep them stable. They tend to bounce around. The ocean is at the level it is because that is where it is most stable

Here are some average levels in nature:

Calcium 400- 425ppm
Magnesium should be 3X your calcium reading or in this case 1200 - 1275ppm.
Alkalinity 2.0-3.0 meq/L (5.6 - 9.1dKH).

Here is a link that has a calculator that you may find helpful to figure out what the ionic balance should be between calcium and alkalinity.
http://www.andy-hipkiss.co.uk/index.htm?http://www.andy-hipkiss.co.uk/caalkcalc.htm

Regards,
Kevin