Definitely increase mag then. You said you're using salifert for mag? Also, the icp shows your phosphate at 0.01 which could be another culprit (less likely than mag but at that low of a level it's a risk). You have several trace elements at low or 0. How often do you do water changes? If you don't, how often do you dose trace/minors?
.7 or .07?
.07, little typo there
OK, thought so. I am ordering another icp test and see what its at.
What test kits are you using?
If you’re using a hanna ulr phosphorous, it’s accurate. Salifert mag is also legit. The values you posted above, are those pretty current? (Like in the past couple of days)
Similar ones to you, I’d also trust hanna ulr phosphorous, and maybe even salifert mag over icp. Test again today and let’s triple check those are in a good range. What did the last test you ran show before the recession? Is the recession still occurring? If so, what did the most recent test show?
1380 is not a problem but is on the lower side. If mag continued to drop after the icp test then there would definitely be issues. Since we don't know much of the dosing schedule, that's what we need to check it if the recession is still occurring. Still too many things we don't know. This wreaks of mag deficiency to me though.
1380 is 100+ more than natural seawater. Consumption of Alk and Ca would have to be huge to drop Mg from 1380+ to low levels.
We have no clue how much time stood between the icp/salifert tests and the recession which is why I'd like to confirm. I wouldn't rule it out and at this point isolating/verifying as much as possible is important.
From RHF about Mg consumption: "It is not more than about 1/10th of the calcium consumption. Anything substantially larger is testing error of some sort."
That assumes only corals are consuming the mag. Once again, we know what the ICP tests were but have no clue when they were taken relative to the recession. Given mag deficiency is one of the more common culprits of such recession, it's certainly worth checking out.
