Well, now, magnesium REAL low...

[20 20]

29 gallon reef
15 gallon sump (approximately 10 gallons water, for a total volume of 39 gallons)
Been running for about 8 weeks.
ph: 8.4
Ammonia: 0
Nitrite: 0
Nitrate: 20
SG: 1.025
alk: 130 ppm (or 7.5 dKH, or 2.68 meq/l)
calcium: 450 ppm
phosphate: 0
temp: 77
MAGNESIUM: 270 PPM

Magnesium at 270 ppm, tested using a Salifert test kit. From what I understand, it should be 1250-1350. So, I've got a ways to go. I've got Kent 'Tech-M' magnesium supplement. The directions say to add 1 ml per gallon per day, raising the magnesium 18.3 ppm per day. At that rate, it'll take 56 days to get the level to 1300 ppm. Is there any easier way to raise the level safely?

 

[Phyl]

After I tested my mag 2 or 3 more times I'd start doing water changes. Your other numbers look off to me too. Your Ca should be more like 400-450, your alk should be between 9 & 11 (or between 3.25 & 4). You may want to have your results checked by your LFS to ensure that you've go the instructions down. If your numbers really are that out of whack I'd be doing 30% water changes to get things back in line.

Good luck!

 

[20 20]

The calcium reading in my first post was a typo, I had it at 45, should have been 450. I've corrected the first post. And for the alk, it is 130 ppm, which is the same as 7.5 dKH, or 2.68 meq/l. Being a newbie, I'm not sure which reading 'type' is most often used. So, the numbers actually make more sense than you first thought, at least I THINK they do! And if they do, that still leaves a REAL low magnesium level.

 

[seafan]

Supplements may also help, I use C-Balance, but improper use of supplements could lead to algae blooms.

 

[Brenden]

What brand of salt mix do you use? How often and what size water changes do you do? I am curious about how it got that low in the first place. Do you currently add any suppliments to your tank?

 

[Phyl]

I also find that level hard to imagine given a normal water change schedule. Could you test a new batch of salt and see what that comes up at? Have you double checked your test kit with the LFS?

 

[20 20]

Well, turns out I made my readings correctly, but read the instructions wrong on how to convert that last level in the syringe into ppm. So, my Mg level two days ago was 1215. I added Kent Marine's "Tech M" to raise the Mg level. I was out of town last night, so didn't take any readings until tonight. Mg is now as 1425. But, the alk level has dropped to 110 ppm. It's always something, eh?

 

[Phyl]

Truly always something! At least the low alk is a more common problem with easy answers! The alk in our stock tank was all over the place until we put a fan over it. The CO2 was getting trapped above the water and was suppressing the alk. All's well now that we've got the fan running (except for the 6g a day of evap)!