Rapidly Lost Acroporas-Low Calcium?

[gdtpgh]

I am not sure why but my calcium level dropped below 300. I was dosing kalk and doing small 5 gal water changes every week. I was testing calcium using a lamotte's kit and thought I was around 400+ and everything was good until I lost two acroporas. I sent a sample to Aquarium Water Testing and they said my calium was over 100points lower than I expected.

The tank was setup in July...I converted an older 55gal to a 125. The acros were new and not a part of the original 55.

Can a low calcium level kill an acro so suddenly? For a few months it was ok with polyps out and the next it was a skeleton. I have montiporas that are fine and growing and coralline is covering the glass. I'm just confused. Could it be something else that only hit the acros and nothing else? I looked for red bugs but saw none. I do have a small outbreak of planaria but I'm keeping them down by siphoning.

Any help would be appreciated.

By the way here's the rest of the AWT results - don't ask me why Mo and Sr are high - I don't dose them. I've since started to add some iodine. I am also dubious of the Silica number. I use RO/DI with a new Spectrapure Silica Buster filter.

Ammonia (NH3-4) 0.011 Good
Nitrite (NO2) 0.002 Good
Nitrate (NO3) 0.0 Good
Phosphate (PO4) 0.01 Good
Silica (SiO2-3) 1.1 High
Potassium (K) 307 Low
Calcium (Ca) 297 Low
Boron (B) 3.7 Good
Molybdenum (Mo) 0.2 High
Strontium (Sr) 14.2 High
Magnesium (Mg) 1416 High
Iodine (I¯) 0.00 Low
Copper (Cu++) 0.02 Good
Alkalinity (meq/L) 3.42 Good

Thanks,

George

 

[camaroracer214]

the ammonia and nitrite are too high. even a small amount can be dangerous to have. i wouldn't expect two colonies to die because of low calcium. do you know what type of acros they were. perhaps you have a red bug infestation that the corals couldn't overcome.

 

[gdtpgh]

Ammonia at .011ppm and Nitrite at .002ppm is too high? I'll take your word for it but that just seems to go against what I use as my benchmark...Randy Holmes Farley's recommendations here http://www.reefkeeping.com/issues/2004-05/rhf/index.php
I understand they should be zero but can I even get them that low?

I am not 100% sure of the types of acros. One was purple perhaps a valida. The other was just something my local fish store had and wasn't sure of the exact name.

I suspected red bugs but couldn't find any. Wouldn't they also go after the montiporas and the other corals too?

 

[camaroracer214]

red bugs only go after smooth skinned acros, from everything i've heard. montis and other acros are not affected by red bugs. i've never had red bugs, but from everything that i've heard/read about them is that red bugs only go after certain acros.

did you test your pH and temperature? if your pH or temp fluctuates too much this can cause a lot of damage as well. i recently met a guy who was moving and has had to keep all of his beautiful sps corals in a large tub in his garage. his temp and pH are really the only things fluctuating and this has caused devastation.

but i do think that those nitrites and ammonia are a little to high. closer to zero is always better. btw, how old is your tank and what kind of lighting are you using?

 

[gdtpgh]

I have a pH meter that I calibrate monthly. There is a swing in the pH between day and night. Its high is around 8.2 and the low 7.9. The temp is 80 with the lights on and at night falls a degree sometimes two but it's a slow transition. In the summer it was a bit higher even with my air conditioner on and a fan blowing on the surface. Summetime temps were 82 and 80.

I think I'm doing everything to keep nitrites and ammonia as low as possible. There's only a handful of small fish in the tank and I feed only what they can eat. My skimmer appears to be very effective so I'm at a loss as to what I can do to get them any closer to zero. I'll be sending another water sample to AWT to see if there is any change in my values since the last test.

My lighting unit is the Coralife 72" Aqualight Pro with three 10K HQI Halide bulbs and two rows of Actinic blue bulbs. The light is approx 8 inch above the surface of the water.

The tank was setup last July but was it wasn't a completely new setup. I transferred the the contents from a 55gal into this 125gal. I added additional new rock as well as new live sand and a refugium. The old 55 gal tank was used as the sump for this setup.

George

 

[camaroracer214]

the only thing that i can think of then that would cause a sudden death in coral tissue is a parasite. look at various times at day and night to see if you see anything. sometimes the larger encrusting tube worms can cause a lot of damage to an sps colony. i lost several nice branches because one of those little guys was casting a net onto the colony and bleaching out the tissue. sometimes they can grow directly on the coral...check all around the base and between branches.