magnesium help please

[Vincent100]

hi all
350 redsea reefer .......about 300 liters of water
about 90 corals , most are frags but some are not , most are lps with about 10 sps

calcium between 420ppm and 430ppm on my salifert test kit so i take it its at 425ppm
Alk is at 7.7 dkh / 2.73meg/L
ph 8.1
1.025

magnesium is were i need some help
last night i tested and it was at 1290ppm
i dosed 30ml of magnesium lastnight which should of took it up to 1300ppm.
on the bottle of redsea mg supplement i use it says that 1ml /100 liters (25gal)...1ppm mg
so 30 ml would rise it by 10ppm ....am i right lol
anyway i retested today and my mg was at 1260ppm so in about 12 hours iv dropped alot
does this sound right for the amount of corals i have ....over 90
iv just dosed another 30ml but thats only gonna take it up to 1270 ppm
how much mg can i dose safely in a day .....feels like im fighting a loseing battle here

thanks

 

[Randy Holmes-Farley Verified Community Expert]

The magnesium change is testing error. It is not likely to be changing more than 1 ppm per day. Just watch it over a longer period of time.

 

[Vincent100]

thanks Randy

i went and got a new kit the other day because i was thinking my other one wasnt right , now the new one is doing the same
their both salifert and well in date
im following it to the T and maybe testing 3 or 4 times and it always comes up the same
i gonna go to my lfs tomorrow and get them to test with theirs and than mine
would the 60ml iv added over the last 2 days be bad ?

thanks randy

 

[Randy Holmes-Farley Verified Community Expert]

Magnesium depletes very slowly, and it takes large amounts to make a boost.

What product did you add 60 mL of?