Magnesium levels?

[Douglas]

Can/do Magnesium levels fluctuate during the day? Without dosing Mag in three days, my level has fluctuated from 1350 at 5:00am yesterday to 1550 at 7:00pm tonight. I tested it twice, because i couldn't believe the reading myself. I have been trying to determine how much Mag is either consumed, or used in my tank, so i can place magnesium on my doser. But with inconsistant readings, it's becoming hard to determine this amount. Any ideas would help. Thanks.

[mark]

Measured Mg and different times over periods of days and always seemed to go down but then never did back to back am/pm testing. Does seem though like a really large swing.

Am interested in what others say as just started dosing Mg for bryopsis.

[Douglas]

After thinking about it for a bit here, I have come to my own detemination, and hopefully this is correct. With the water level lowering during the day, due to evaporation, The magnisium level rises, like my saline level. The auto topoff kicks in, and tops off the tank over night, usually. Will test in the morning, like usual. And will do water change, to try to lower possible overdosed mag level.

[mark]

don't make me do the math, but if due evap, still seems a huge swing.

[lorenz0]

what are you measuring with? when ever I test, I always test 3 times to make sure my final conclusion is consistent

[Douglas]

I'm using an Elos Mag test kit. Bought two weeks ago. Best before date 12/12

[spawn]

Doug are you "sure" that your drop count wasn't just "off" by 4? 33 - 6 is 1350 & 37 -6 is 1550
Can/do Magnesium levels fluctuate during the day? Without dosing Mag in three days, my level has fluctuated from 1350 at 5:00am yesterday to 1550 at 7:00pm tonight. I tested it twice, because i couldn't believe the reading myself. I have been trying to determine how much Mag is either consumed, or used in my tank, so i can place magnesium on my doser. But with inconsistant readings, it's becoming hard to determine this amount. Any ideas would help. Thanks.

[Douglas]

Tested for Mag this morning at 5:00 am. "1500". Will do a water change later this evening. Still boggling my mind a bit. Can't figure out why such a spike. I am using a different mag product, so that could be it also.