Magnesium issue

C_Everett95

New member
My calcium is sitting at 380, alkalinity still high at 15 and I will need to do a few more water changes, and my magnesium is 1110. I was looking at the mix it yourself magnesium chloride and magnesium sulfate flakes from BSR to raise my Magnesium, but I am aware that it will also raise my SG as well. Magnesium being low I know it will be hard to keep my alkalinity and calcium in line where they need to be. I have done a few 20% water changes over the course of a week to being my Alk down some, and I'm going to be doing a few more throughout this next week to get my Alkalinity down, but before I go ahead and do this and go wasting money on water and salt, should I deal with the magnesium problem first? If so how should I go about it, I don't want to try to get the other levels in line only to fail because the magnesium is too low. all other parameter are in check though besides pH which seems a little lower than the last time I checked it. Thanks in advance! :)
 
What size tank, what brand salt, and how are you testing? What additives for Ca and Alk are you using? Sounds to me like if you did a couple 20% water changes over the course of a week, you would have replaced most of the old water with new, and should be much closer to the levels of your salt brand than you describe. I'd mix up a batch of ASW and test those levels first, to make sure somethings not up there
 
What size tank, what brand salt, and how are you testing? What additives for Ca and Alk are you using? Sounds to me like if you did a couple 20% water changes over the course of a week, you would have replaced most of the old water with new, and should be much closer to the levels of your salt brand than you describe. I'd mix up a batch of ASW and test those levels first, to make sure somethings not up there

65 gallon (36x18x24), instant ocean salt is the only one I've used so far, and I have heard it's a little low in some nutrients but I wouldn't think it would make it that low.

I test alk, calc, and mag all using salifert test kits. At the moment I don't have a Kalk drip or reactor or anything to maintain calc or alk as my tank just finished cycling a few weeks ago so im not really too far into any of this yet, and I've only relied on nutrient from the salt during water changes. Only thing in my tank is a small CUC, two zoas, a mushroom and a small frag of GSP, only reason being I took them off a friend who gave up the hobby.

I have done three 20% water changes over the course of last week to try to bring the alk down a little and it has, but not to where I want to be which is around 9 or 10. I'm out of salt at the moment after last nights water change so I have a new bag being delivered tomorrow sometime. I just don't want to continue to fight the alk and calc levels trying to get them stable of my magnesium is going to prevent that. After last nights water change mag actually seemed to have dropped from 1140 to 1110, and calcium from 400 to 380, but that could just be judgement on my part.

I know I probably sound like a major newbie and jumped the gun on this but that's why I'm trying to correct this and learn before going to much further. A couple of more small steps I probably need to take. Thanks for the reply and for your time jml
 
Kind of had the same situation not too long ago (last week).

Found out my refractometer was off and salinity was low. It threw everything out of whack.
 
Kind of had the same situation not too long ago (last week).

Found out my refractometer was off and salinity was low. It threw everything out of whack.

I guess it's always a possibility, but I'm thinking it truly is low magnesium, probably because instant ocean is one of the cheapest sea salts. But I also don't use a cheap refractometer so idk It was I believe $40-$50 on Amazon. Maybe it needs adjusting, honestly I couldn't say.

I'm sure the salt I use lacks those components where they need to be. Only reason I'm thinking it's not my refractomerer is that even testing my LFS pre mixed RO/DI Salwater it reads at 1.024 which is what he told me he mixes it at when I asked him before purchasing it. I personally mix mine per the boxes instructions at 1/2 cup per gallon of water, giving me a 1.026 mix. I'm planning on testing the mix first before my next water change to see if maybe it's the salt that's lacking the nutrient, like said above, after three 20% water changes all the old water should be basically renewed and sitting at the portrayed levels of the brand of salt in using. I guess we'll just have to see. :(
 
It threw everything out of whack.
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Test your newly mixed salt, maybe you have a bad batch? IO should not mix at 15dkh alk.

Well I know the original problem was probably senselessly using a ph buffer. I only used it twice and after research won't be using it again. But after three water changes a majority of the water would be new assuming that that alkalinity spike would have been removed by now. I plan on doing a water change tonight and will test the new mix and the tank levels post water change and give some updates tonight to see where it sits. Thanks for the reply bud.
 
UPDATE:

Have now done my 4th 20% water change. New mix of salt was (calc 400, alkalinity - didn't register...., magnesium 1350

A couple of hours of letting my new water mix in my tank the new params were (cal 380, alk - still 15 as originally stated..., and magnesium 1170. The mag tests specifically say if mag is low then it'll be hard to keep calc and alk levels stable. As for why my alk was so high in my new mix I have no idea and it's really bugging me. Instant ocean can't be that bad... So I guess I'll be doo my research on fixing a mag problem and probably order some magnesium chloride and sulfate and find out how to properly dose without raising my SG :(
 
I assume your using the same box of salt throughout this endeavor?

There has to be a problem with your alk test. There's no way a box of fresh salt reads 0, and your tank reads 15.

I would try buying a Hannah checker for alk or bring a sample to your lfs to test. I have found, when in doubt, if something seems REALLY crazy, it's something I'm doing wrong
 
I assume your using the same box of salt throughout this endeavor?

There has to be a problem with your alk test. There's no way a box of fresh salt reads 0, and your tank reads 15.

I would try buying a Hannah checker for alk or bring a sample to your lfs to test. I have found, when in doubt, if something seems REALLY crazy, it's something I'm doing wrong


Correct I have only ever used instant ocean, and my tanks only been running for about two months but all other parameters are where they need to be, well nitrates and ammonia and what not.

The alk isn't reading 0, in sorry I should have been more clear, the salt mix was higher than the test can read which is 15.7dkh.

I would think by now alk would have significantly dropped with all the water changes over the past two weeks. And yes I got a brand new bag of salt mix yesterday afternoon so I don't think it's a bad batch.

Currently in using salifert calc, alk, and mag tests. I'll try taking a sample to my LFS and see if maybe I got a bad test :/

I may get a Hannah checker in the near future but my
Budget is just about maxed out for a couple of weeks, as I'm still in the process of buying the lighting system I really want.
 
Where is the tank located? How much access to you have to fresh air?

Inside of a doorless closet area, opposite of the bedroom window and away from direct hot/cold air of the houses ac. The tank has no lid so it's able to breathe. I also have a bedroom window unit basically running all day due to my room getting extremely Hot in the summertime.

I'll attach some photos
 

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you could leave your mag alone for the sec and buff your cal this will drop your ak and due to your mag being low the cal will drop. do this a few days till you get to where you want to be ak wise then boost the mg to 1250-1350 and the cal will hold. good time to be doing the numbers on what affects the tank
 
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