Mg staying too high.

[reefer125g]

So mag is been running in 1500 for past few months . Can't seem to get it down . Doing regularly water changes 2 a month
20 gallons each time with regular IO salt and that's testing at 1300 or so . Running a CA reactor and it's keeping my Alk at 9 CA at 426 but mg 1500 to 1510. Running Reborn media. All other parameters are well in spec. I normally would not worry but tips of Acros are starting to burn . If I cut CO2 or drip down other numbers fall .

180 gallon tank attached 40 breader frag tank with a 50 gallon sump .
Kessil 360 tuna
4x t5
Euro reef skimmer
Uv 36 watt
3x core 20 returns
6" CA reactor with electronic CO2 doser

 

[dz6t]

It is possible that the reactor media is high in Magnesium.

 

[reefer125g]

It should not be it's Reborn so it's coral skeleton. Should be the perfect balance.

 

[dz6t]

Depends on where the media was harvested.
Is your media looking like big chunks or small to medium pebbles?

 

[dz6t]

On the other hand, 1500 ppm is pretty good. I won’t worry about it unless your calcium level is over 500 ppm.

 

[afboundguy]

I agree with Dong 1500 is nothing to worry about as long as calcium and alkalinity are fine...

 

[reefer125g]

Depends on where the media was harvested.
Is your media looking like big chunks or small to medium pebbles?

Big coral skeleton

 

[reefer125g]

I agree with Dong 1500 is nothing to worry about as long as calcium and alkalinity are fine...

I agree with Dong 1500 is nothing to worry about as long as calcium and alkalinity are fine...

Ph 8.4 , Alk is 10.2 , Ca 426 , Mag 1500
Phosphate 0.0 nitrate is 0.01 salinity 35.ppm ORP 440
Still burning tips of SPS

 

[NeverlosT]

are you sure of the accuracy of the Magnesium test?

1500 is high but not terrible. If your ALK and CA are acceptable I'd hesitate to do anything big.

I have never heard of reborn causing high magnesium. In fact, people usually add Dolomite to the reborn to bring the magnesium level of effluent up.

I suggest double checking your test kit or have someone else test as a check.

 

[NeverlosT]

zero nutrients, high pH high alk, I fear that may be the cause of your tip issue.

If I were to change anything here it would be slowly increasing nutrients.

 

[Mixed Reefer]

Ph 8.4 , Alk is 10.2 , Ca 426 , Mag 1500
Phosphate 0.0 nitrate is 0.01 salinity 35.ppm ORP 440
Still burning tips of SPS

Are you sure it’s not growth?

 

[dz6t]

0 phosphate?

 

[Reefried]

I agree that zero nutrients and a 10+ alk may be the cause. 1500 wouldn’t bother me too much. I personally subscribed to the Randy Holmes-Farley method of worrying about Mag!! The RMM!!!

 

[dz6t]

There are nitrate and phosphate receptors on coral skins, corals do take in phosphate actively.
A guy who runs a coral farm in Europe said that he believed in keeping phosphate at 0.1 to 0.2 ppm. He also said that nitrate could drop to 0 but not for phosphate.