Need help with dosing magnesium.

[Sailfinguy21]

My magnesium was 1080 and well im having issues with my sps corals.. i lost a hawkins coral.. and 3 other acros are not looking for.

Thats when i had my water checked and well found out i had low magnesium. Anyway i bought a test kit myself as i hsve all the others but it.. and i bought a half gallon premix of magnesium my local fish store was selling.

I know i can buy it online and mix it myself but i was kinda ina hurry to get the magnesium up.

She told me it was the BRS powder most of the stuff they sell is from brs anyway. So i paid the 20$ even though i think it was a huge ripoff but i needed it lol.

Anyway the bottle says to do 5ml per 20 gallons.. so i dosed 30ml as my tank is 135 gallons. I checked my magnesium a few hours later and no change.. 1080 still.

Waited overnight.. still no change... So i dosed 60ml this time... still no change... i dosed 120ml still no change... and todsy i just put in 300ml and ill check it again but im starting to wonder if they sold me RO water..

I buy corals from this place all the time and they have always been cheaper then everywhere and are good people.. but i dunno about this stuff.


Am i right to suspect something is wrong ? Or does this BRS magnesium really take this much to raise magnesium ?...

Frustrated i just did a 30% water change with reef crystals and my mag webt from 1080 to 1260. So clearly the salt mix raised my magnesium.


I dosed the 300ML after my water change... so well see if magnesium goes up from 1260.. but i dunno if it doesnt ima go back and return this stuff.

Anyone have any input ?

 

[saltyhog]

Without knowing how they mixed it and the size of your tank it's impossible to really say. What is your calcium and alkalinity? What is your total tank volume? What test kits are you using for these three parameters?

 

[Sailfinguy21]

135g. Salifert. Alk 10. Calc 460

 

[Sierra_Bravo]

Use this calculator: http://reef.diesyst.com/chemcalc/chemcalc.html For the BRS mix, choose the entry for "Randy's Recipe's Part 1 and Part 2"

As long as they mixed it correctly, raising your Mg from 1080 to 1350 will require 2,939.5 ml. You may just not be making a dent.

 

[Mastiffsrule]

Use this calculator: http://reef.diesyst.com/chemcalc/chemcalc.html For the BRS mix, choose the entry for "Randy's Recipe's Part 1 and Part 2"

As long as they mixed it correctly, raising your Mg from 1080 to 1350 will require 2,939.5 ml. You may just not be making a dent.

Evening


Beat me to it. brs also has a calculator. Raising mag usually take a lot to see movement. To get you to 1100 would take about 200 ml.

Randy’s calculator is a great thing to use

 

[Sailfinguy21]

I see so in essence i paid 22$ for 1800ML bottle that wont even raise my mag LOL... yea i think ima return this to the store... had i known that i wouldnt hsve bought this.. its cheaper just using reef crystals lolss. And thats expensive.

Ill buy my own mix and mix it... had no idea this store was trying to bank on this crap like this.

 

[Ecvernon]

It would have been more economical to do a series of water changes vs dosing that much as you figured out. How did the Mag get so low?

 

[Sailfinguy21]

I havent done a water change in 3 months lol and i forgot about checking magnesium not jist calcium and alk haha.

I was doing seachems 2 part dose which has calcium and mag but i guess it wasnt enough

 

[Sailfinguy21]

Well i did my 2nd 25% water change.. mag went from 1080 to 1250 first 25% change yesturday. And today it went from 1250 to 1350 with the 2nd 25% change.

Using reef crystals.

 

[Sailfinguy21]

Im gonna maintain 10 dkh... i nkticed the calcium and dkh for the water changes stayed at 10 and 460.. So ill try to keep it at that.. this wsy when i do water changes it wont shock my corals