Coral just died on me

[bryan oestreich]

So I test my tank weekly. Tank has been steady parameters over the last 2 months And my brain coral has died over the last 2 days. Noticed mag dropped way low. Feeding has been the same for over a month. Once a day. Spot feed 2-3 times a week for coral.

Parameters as of today:
Temp 77
Salinity 1.025 (refractometer)
Alk 10dkh (salifert)
Calcium 360 (usually 380) (api)
Phosphate .1 (salifert) (usually .03)
Mag 840 (up until this week it has tested at 1240-1280) (red sea)
Nitrate 10-20 (api)
Nitrite 0 (api)
Ammonia 0 (seachum)

I don't dose anything in the tank and I was going to start dosing calcium to get it up to 420 range to help coral growth.

This last month I switched to mixing my LFS RO/DI water using instant ocean reef crystals doing 20% water changes weekly. Switch due to cost. Buying the premix salt water was costing to much weekly.

Nothing has been added for over a month and nothing has died but the brain coral yesterday. Does anybody have any idea why it died so fast or why my mag dropped? I'm going to test again later hoping for that test from earlier today to be bad due to human error.

I plan on testing the RO/DI water I get from the LFS store and test the water after I mix the salt because I never test above 380 for calcium and the instant ocean reef crystals should be higher than that and doing 20% water changes weekly should restore any takem from coral which I don't have many so can't see that effecting it

Mean while I would like to hear what anybody else has to say
Pictures are from the died or dying coral taken today and the one alive is from a week ago

 

[Tahoe61]

That looks to be an Acan.

Testing for magnesium can be tricky, test kit and human error are common. It's unusual for me to see a mag level truly that low. Any water changes would correct the value. I would retest against another testing method/kit. I use Red Sea for mag and have found it to be fairly reliable. When I do get a value that is so far off the base line I retest, check reagents.

I would not add any dosing products until you nail down a true mag level. Ca and Alk values are not going to stabilize if your Mag is truly that low.

 

[bryan oestreich]

That looks to be an Acan.

Testing for magnesium can be tricky, test kit and human error are common. It's unusual for me to see a mag level truly that low. Any water changes would correct the value. I would retest against another testing method/kit. I use Red Sea for mag and have found it to be fairly reliable. When I do get a value that is so far off the base line I retest, check reagents.

I would not add any dosing products until you nail down a true mag level. Ca and Alk values are not going to stabilize if your Mag is truly that low.

Okay say if mag is okay. What could of caused the sudden death?

 

[Baby Ray]

Sometimes corals die for no reason...... it just happens.

 

[bryan oestreich]

This might be a better picture for color

 

[ironman31]

Mag is way too low to keep lps happy

 

[bryan oestreich]

So retested my mag is at 1280. Using red sea I'm assuming I didn't mix the first reagent good enough.

So now the question why didy coral up and die

 

[bryan oestreich]

Sometimes corals die for no reason...... it just happens.

Ya I mean I don't have any other problems with tank but jus this yesterday

 

[bryan oestreich]

This is my tank

 

[ironman31]

I'd say retest mag a few times just to be sure your at 1280... testing mag is tricky sometimes especially if using red sea kit

 

[SantaMonicaHelp]

Sometimes seemingly harmless fish or other animals can damage corals...
-MJ

 

[Tahoe61]

I would not make too much of the corals death if your parameters are in line. As posted it happens, even if every other coral in the tank looks good.
If I had a dollar for every frag I lost........
Not sure of lighting type but you may want to keep the LPS in the sand bed for lighting acclimation for a week or so.

 

[bryan oestreich]

I have 2 of the 16" dimmable ones. I run at 50% blue and 25% white. Blue for 10 hrs and whites for 8hrs. There 16" above the tank

 

[that Reef Guy]

Lighting Too High
Pests
Fish Picking on it

Those would be 3 common reasons it died.

Feeding them is Huge.

https://www.reef2reef.com/threads/s...nthids-happy-healthy-and-growing-fast.250791/

I have lots of Helpful Tips in that Thread.

Even though I Posted it in the Zoanthid Forum all of those Tips will Apply to Acans too.

 

[that Reef Guy]

Don't use the API Kit.

It is not accurate at all - same with their Alkalinity Test.

I have seen the Calcium off by 100 Points Before!

What are you using to Calibrate your Refractometer with?

With Calcium and Magnesium so Low that is a Sign your Salinity my be too Low.

 

[Lionfish Lair]

If everything else is fine, even other LPS, than I wouldn't do anything different until there was reason.

 

[bryan oestreich]

Don't use the API Kit.

It is not accurate at all - same with their Alkalinity Test.

I have seen the Calcium off by 100 Points Before!

What are you using to Calibrate your Refractometer with?

With Calcium and Magnesium so Low that is a Sign your Salinity my be too Low.

I use red sea also for calcium and there are about 20ppm off between api and red sea. I just use RO/DI water to calibrate the refractometer last month I brought my water in to LFS to test and my salinity matched theres.
wouldn't I have signs in the tank if the salinity is there far off

 

[that Reef Guy]

I use red sea also for calcium and there are about 20ppm off between api and red sea. I just use RO/DI water to calibrate the refractometer last month I brought my water in to LFS to test and my salinity matched theres.
wouldn't I have signs in the tank if the salinity is there far off

Calibrating with RO Water will Make your Salinity Incorrect by a Few Points.

You need to get something like PinPoint RO Calibration Solution or Accurasea by Two Little Fishies.

Not saying that Killed the Coral but you definetly do not want your salinity to be off.