Mag dropped

bryan oestreich · Jun 30, 2016

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

Randy Holmes-Farley · Jul 1, 2016

I do not know what the problem is, but there is zero chance the magnesium dropped from 1200+ ppm to 840 ppm in any reasonable time frame. Real magnesium depletion is usually 2 ppm per day or less, often almost none. There's just no mechanism for a rapid drop.

Uliulimaka · Jul 1, 2016

I would re-test with another test kit. That's a pretty massive drop over a short time. I would also recommend trying Kent brand salt. Can order it online for under $50 for a 200 gallon case. Mixes up easy, and packed with good levels of mag. and calcium.

bryan oestreich · Jul 1, 2016

retested twice using red sea and it came back to 1280 so I am assuming human error on testing the mag but what else can result in the coral death?

Uliulimaka · Jul 1, 2016

Are the pictures of the same coral?

bryan oestreich · Jul 1, 2016

Uliulimaka said:
Are the pictures of the same coral?

yes. the alive picture one was taken 2 weeks ago. the dead picture was from 2 days ago and it died within 24hrs.

Uliulimaka · Jul 1, 2016

No shrinkage or tissue recession prior to the 24 hour period it died in? If so thats odd. Though I have had Acans do the same thing to me. Fine one day and melting the next.

Uliulimaka · Jul 1, 2016

I would say check for stray voltage in your system. Usually it will have an "overall" effect. Though some organisms are more succeptable to lower levels of voltage.

bryan oestreich · Jul 1, 2016

Uliulimaka said:
No shrinkage or tissue recession prior to the 24 hour period it died in? If so thats odd. Though I have had Acans do the same thing to me. Fine one day and melting the next.

I saw it shrink up the day before, but I figured it was from a shrimp or crab just walking over it or something like usually why they retract but the next day I see it completely done and basically an empty skeleton and one side was complet

Uliulimaka said:
I would say check for stray voltage in your system. Usually it will have an "overall" effect. Though some organisms are more succeptable to lower levels of voltage.

stray voltage as? like a cord in the water or broken heater? I cant see the heater being a problem because it really hasn't been touched or bumped since its been in the tank but wouldn't fish or other inverts or coral show effect of some type of voltage getting into tank?

Uliulimaka · Jul 1, 2016

Sometimes it's as simple as a grounding issue. Do you use a grounding probe? Or are you plugged into a GFCI outlet? Basically it is voltage leaking from a piece of equipment. May not be detectable by you, yet can cause issues with sensitive corals, inverts, fish, ect.

bryan oestreich · Jul 1, 2016

Uliulimaka said:
Sometimes it's as simple as a grounding issue. Do you use a grounding probe? Or are you plugged into a GFCI outlet? Basically it is voltage leaking from a piece of equipment. May not be detectable by you, yet can cause issues with sensitive corals, inverts, fish, ect.

im using the outlet in my house which I would believe is GFCI and no ground probe. I have all the equipment plugged into a surge protecting power strip

bryan oestreich · Jul 1, 2016

how can I find out if it is leaking voltage? is there a way I can test something?

Uliulimaka · Jul 1, 2016

If the outlet has a test and reset button on it, its a gfci. You can use a volt meter to test for voltage. I don't have a link handy, but if you search stray voltage in aquarium, you should find some good articles.

bryan oestreich · Jul 1, 2016

Uliulimaka said:
If the outlet has a test and reset button on it, its a gfci. You can use a volt meter to test for voltage. I don't have a link handy, but if you search stray voltage in aquarium, you should find some good articles.

okay the one im using for the tank doesn't have a GFCI outlet

bryan oestreich · Jul 1, 2016

Uliulimaka said:
If the outlet has a test and reset button on it, its a gfci. You can use a volt meter to test for voltage. I don't have a link handy, but if you search stray voltage in aquarium, you should find some good articles.

im going to test for stray voltage tomorrow when I get the time. hopefully if it is stray voltage, it can be an easy fix