need some help with magnesium

[dodger745]

looking for advice/help

I have a 180g mixed reef. my mag is always testing low 1050-1100 ppm.

I have bought some seachem magnesium and used it but It seems I need a very large amount to bring my level up to 1300 range.

What is everyone using for magnesium supplements?

and what suggestions do you have to raise the level in my system safely.

I am running a large korallin calcium reactor to maintain cal/alk. those parameters are a bit low at 380 cal and 7.7dkh alk.

I do not have a dosing pump.

 

[Randy Holmes-Farley Verified Community Expert]

What salt mix are you using? What salinity?

Magnesium that low is usually a testing error, the salinity being too low, or a reef tank with no water changes and inadequate magnesium additions for a very long time. True magnesium depletion is on the order of 1-2 ppm per day, max.

It does take a huge amount of supplement to boost magnesium significantly. I'd use a DIY, with ingredients from Dr Foster and Smith or BRS, etc., and/or the drug store:

Do-It-Yourself Magnesium Supplements for the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com

 

[dodger745]

Instant ocean. I do a 25 gallon water change like clockwork every 2 weeks. Salinity is 1.026.

 

[dodger745]

Also I use Salifert for all of my testing

 

[reefndude]

It does take a lot of mag supplements to increase. I dosed tech m to battle bryopsis. 150 ml increased mag about 20 ppm with about 150 g water volume

 

[dodger745]

I've been reading about that supplement. I need to either order a gallon of it or the 4 kilo bucket of the seachem mag. I'm going to read the posted article about the diy mag as well. From what I've seen it's not recommend to add very much at one time

 

[Randy Holmes-Farley Verified Community Expert]

Instant ocean. I do a 25 gallon water change like clockwork every 2 weeks. Salinity is 1.026.

Then I expect magnesium isn't really that low. IO has plenty of magnesium and it is not depleted at a rate that would get you to 1050 in any reasonable period of time when doing water changes.

I'd get a double check on that kit reading.