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why cant i keep magnesium up

1403 Views 16 Replies 11 Participants Last post by  LobsterOfJustice
for some reason my magnesium will not stay up above readings are
calcium 400-450
alk-km 10-11
nitrites 0
nitrates 0
ammonia 0
ph 8.2
salinity 1.023
i have auto top off so water levels stay the same on a regular basis...
i dose with c balance 2 part... twice a week like there something im missing
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If you do your normal water changes,and your corals and coraline algae is doing fine,you shouldn`t have to worry about magnesium...What I would do is look at the organisms that are in the tank,and not worry about chasing a magic number...Consistantcy or stability makes all the difference.......
If you have Coralline algae well established or rapidly growing then it could be what is using it up? Aquarium Chemistry: Magnesium In Reef Aquaria — Advanced Aquarist | Aquarist Magazine and Blog
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Just curious - you ask about keeping magnesium up, but you didn't mention anything about dosing it to get it to the level you want. If your calcium and alkalinity are at desirable levels, then you need to dose magnesium to lift that level. Once magnesium is at the level you want it to be, the 2 part you are using should keep it in line.
I've been dosing it some using sec advantage magnesium
Not sure how many gallons in your system? My system is 100 gallons in the water column so using Seachem Advantage Magnesium I would have to add about 16 ounces (2 cups) to get mine up from 1250 to 1350. I found it easier to use a higher mag salt when I do water changes and just dose once in a while. Since I'm on a budget, I use BRS mag recipe to keep that cost low. How much are you dosing and how many gallons in your system?
Caution though, if you are wanting to bump to 1350, do it 1/3 per day and do it slowly, when you are not dosing your other additives. Frankly, at 1.023 I would consider doing a few 10% water changes at 1.026 and you might find the problem resolved if you are using reef crystals for example which has a high magnesium level. But that is just me, I keep my tank at 1.026
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Sounds like I may not be putting enough magnesium in it and I used to use reef crystals and I had the same problem and now I use oceanic salt and my aquarium is 125 gallons with a 40 gallon sump
hahahaha sigh. I thought we were adults around here. LOL
If you are using GFO on your tank that can have an effect on the magnesium level on your tank......
Regal. I'm just wondering where you got that theory. I'm not saying it's wrong, but I've never heard it before. I would THINK since Mg has a positive 2 charge in a ionic form and phosphate has a negative 3 charge it would actually repel Mg due to phosphate having 4 oxygens and gfo having three oxygens and all those free electrons are really going to push each other away with a vengeance like two magnets pressed together at the same pole; however, the binding site is iron which has a positive 3 charge which is why it binds so tightly to PO43-. I'm not trying to be argumentative, I just wonder if you can point me in a direction where to do more research as now you've got me curious.
I think it is possible for the Mg to bump a hydrogen and bind to one of the oxygens, but I think it would be a very low Veq related to binding to PO43-. Thoughts?
Wouldnt that require a massive amount of energy to break that ionic bond from PO43-? In chemistry, doesnt the easiest reaction usually win out? Plus, youd have to have a ton of Fe2O3 in your system that youd have to replenish?

My chemistry days were so long ago, Im having trouble knocking all of the rust off..
When you make your saltwater what is the magnesium level before you put it into your system?
It takes a lot of magnesium to change levels... I'm not familiar with the supplement you are using but if you are using a supplement for MAINTAINING Mg, you might have to add the whole bottle to bring it up 100ppm.

There is a ton of magnesium in seawater and therefore it takes a lot to change your numbers. It is the third most abundant ion in seawater after sodium and chloride (i.e. salt).
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