Mag testing

[cjtabares]

I tested magnesium today for the 1st time and it came back at 1000-1050 with Salifert and I am wondering if I need to do anything, and if so what? I have read the test kits can be very inaccurate, and to dose it based on calcium, so have never tested it and hoped the all for reef would keep it where it should be, the tank is only 3 months old with 2 small frags. I started dosing All for reef a few weeks ago and made sure my Calcium and alk were where I wanted them. So I have those where I want them, alk 7.5 and calcium 440. Just not sure what to do about Mag now.

 

[EeyoreIsMySpiritAnimal]

Do nothing.


Thread 'Just say NO to magnesium testing: RMM is born' https://www.reef2reef.com/threads/just-say-no-to-magnesium-testing-rmm-is-born.1017528/

 

[EeyoreIsMySpiritAnimal]

I tested magnesium today for the 1st time and it came back at 1000-1050 with Salifert and I am wondering if I need to do anything, and if so what? I have read the test kits can be very inaccurate, and to dose it based on calcium, so have never tested it and hoped the all for reef would keep it where it should be, the tank is only 3 months old with 2 small frags. I started dosing All for reef a few weeks ago and made sure my Calcium and alk were where I wanted them. So I have those where I want them, alk 7.5 and calcium 440. Just not sure what to do about Mag now.

Why would you need to dose a 3 month old tank that only has 2 frags? You're making things too complicated...

 

[slingfox]

Salifert mag is considered to be a reliable test (that is also what I use). Try testing some freshly made saltwater for comparison. During the first 5 months of my tank my mag was also very low and I had to dose a bunch of mag. The more economical way to do this is to buy the mag powder from BRS and mix your own solution using a digital scale. Once my tank stabilized I haven't had to dose mag for the last 2 months. One tip: I run my tank at 1.026 rather than 1.025 SG since the higher salinity increases macro and micro elements.

Edit: I think one issue I had was I was using an unreliable refractometer ($35 from one of the big aquarium equipment retailers) that was showing 1.025 SG when it was really only 1.020 SG. This resulted in low mag levels and dosing. Thankfully I found out the issue and now use a Ver Gee refeactometer. No mag level issues since the fix.

 

[slingfox]

Why would you need to dose a 3 month old tank that only has 2 frags? You're making things too complicated...

In a new tank some parameters can swing for various reason. I agree these is not much need to manage things too closely that early on but it does not hurt to get into a consistent testing schedule and some practice dosing/adjusting parameters when there is not much to lose. With such a low coral load I don't see why dosing AFR would be needed though. Water change should be sufficient.

 

[cjtabares]

Do nothing.


Thread 'Just say NO to magnesium testing: RMM is born' https://www.reef2reef.com/threads/just-say-no-to-magnesium-testing-rmm-is-born.1017528/

This is the post I read, I was wondering if I also needed to maybe get mag to where it needed then not worry about it.

Why would you need to dose a 3 month old tank that only has 2 frags? You're making things too complicated...

My tank is using alk and calcium, so I am dosing 10ml a day on my 50 gal tank to keep up what is being used.

 

[Pod_01]

Mg is required to keep Alk and Ca at correct level without precipitation.

If you trust you test results, increase the Mg. As pointed out maybe it is measurement error.

Also as pointed out on 3 months old tank, dosing may not be required… water changes may be better option.
My experience tells me swings in parameters in new tank may be user error.
When testing make sure the salinity is consistent, swings in salinity may introduce additional errors.

Good luck,

 

[cjtabares]

In a new tank some parameters can swing for various reason. I agree these is not much need to manage things too closely that early on but it does not hurt to get into a consistent testing schedule and some practice dosing/adjusting parameters when there is not much to lose. With such a low coral load I don't see why dosing AFR would be needed though. Water change should be sufficient.

I have been doing weekly 10% water changes. These are my alk and cal when dosing AFR.

 

[slingfox]

I have been doing weekly 10% water changes. These are my alk and cal when dosing AFR.

It seems odd to have Alk drop by 1.1 dkH in two days in a new 50g system with only 2 frags. It is great you are monitoring parameters and trying to figure out ways to address. I don't use AFR since it is an expensive route but I use ESV 2-part and base by dosing on alkalinity level measured once per week with a Hanna checker. I used to test for calcium and mag weekly but now use Randy's method of not testing for mag (instead I do adjustment doses when I add new saltwater and only test mag once a month). I also now only test for calcium every month for two. I only stopped testing for mag and calcium once those levels stabilized which took 6 months or so for my tank. The initial months things moved around a lot due to various issues including faulty refractometer, user error in testing (I was not using the Hanna checkers right), and the uglies making nutrients level swing wildly. If you can make it through the first year you will be good! I am in month 8 right now.

 

[cjtabares]

Thanks for all the replies everyone, hopefully I am not sounding defensive, just trying to give my reasoning behind my decisions.

It seems odd to have Alk drop by 1.1 dkH in two days in a new 50g system with only 2 frags. It is great you are monitoring parameters and trying to figure out ways to address. I don't use AFR since it is an expensive route but I use ESV 2-part and base by dosing on alkalinity level measured once per week with a Hanna checker. I used to test for calcium and mag weekly but now use Randy's method of not testing for mag (instead I do adjustment doses when I add new saltwater and only test mag once a month). I also now only test for calcium every month for two. I only stopped testing for mag and calcium once those levels stabilized which took 6 months or so for my tank. The initial months things moved around a lot due to various issues including faulty refractometer, user error in testing (I was not using the Hanna checkers right), and the uglies making nutrients level swing wildly. If you can make it through the first year you will be good! I am in month 8 right now.

I am using the Hana, could be using them incorrectly, I had a lfs verify my numbers, but that was probably a month ago now, but we were pretty close. My alk tester is probably 10 years old at this point, but has been sitting unused for 5, maybe I should get new vials, or take one from the new phosphate one I bought to check against. Maybe I will try an ICP test.

Definitely going through some uglies on and off.

I use a refractometer and a tropic Marin hydrometer, they both read 1.025.

 

[19Mateo83]

This is the post I read, I was wondering if I also needed to maybe get mag to where it needed then not worry about it.

My tank is using alk and calcium, so I am dosing 10ml a day on my 50 gal tank to keep up what is being used.

That seems like an aweful lot on 2 frags. My 50 is approaching a year old and is LOADED with coral and I’m only using 8ml/day. Personally, I would get your magnesium up to where you want it with brightwell’s magnesion, which won’t interact with the AFR as long as you dose it separately. Once you have your mag baselined you can start adjusting alkalinity and calcium. All three are in relation with each other and you can’t get accurate alk and cal readings until magnesium is on point. Just my $.02 but that was how I was taught way back in the day. Just make your adjustments a little at a time, say 20ml a day until it’s 1350. It’s going to look like a lot but it takes a lot to bring it up.

 

[slingfox]

Thanks for all the replies everyone, hopefully I am not sounding defensive, just trying to give my reasoning behind my decisions.

I am using the Hana, could be using them incorrectly, I had a lfs verify my numbers, but that was probably a month ago now, but we were pretty close. My alk tester is probably 10 years old at this point, but has been sitting unused for 5, maybe I should get new vials, or take one from the new phosphate one I bought to check against. Maybe I will try an ICP test.

Definitely going through some uglies on and off.

I use a refractometer and a tropic Marin hydrometer, they both read 1.025.

Here is one major user error I was guilty of for my first 7 months of the hobby: Some tests when you put in the C2 sample (ie, after you add the reagent to the vial and mix) you need to hold the button on the check down so that it initiates a timer before taking the reading. This is the case with both the phosphate and nitrate checkers. This is not the case with alkalinity if I recall correctly.

If your alk tester is 10 years old it may indeed make sense to replace since some would argue that is one of the most important parameters. Make sure you are using reagent that is not not too crazy far out of expiration. You can also buy new Hanna vials for $11.

 

[Randy Holmes-Farley]

I definitely would not add magnesium until you somehow confirm the result, and if it were me, I would not bother. There was not hundreds of ppm of magnesium consumed in this tank.

The main things to check are that the salinity is not a lot lower than you think, and that the salt mix you are using is a reasonable one.

If you want to do something, first is to check the new salt water with the same kit at the same time as testing tank water.

 

[cjtabares]

Ok, I ordered an ATI ipc test, figured it might help see where I am.

I had my salt verified a few weeks ago at 1.025, my refractometer and hydrometer confirm 1.025, but maybe the icp will also give me a better idea on that. I am using Tropic Marin Reef Pro salt. Maybe I will run some tests on my salt water.

 

[Randy Holmes-Farley]

Ok, I ordered an ATI ipc test, figured it might help see where I am.

I had my salt verified a few weeks ago at 1.025, my refractometer and hydrometer confirm 1.025, but maybe the icp will also give me a better idea on that. I am using Tropic Marin Reef Pro salt. Maybe I will run some tests on my salt water.

Raising the salinity to 35 ppt (sg = 1.0264) from a sg of 1.025 will raise 1200 ppm magnesium to 1267 ppm.

 

[cjtabares]

I brought my salinity to 35 ppt , and monitored my parameters and they seem to be going slowly up. Should I reduce my AFR dose or give it another week or so? The numbers have been pretty close until today, and still don’t seem crazy off.

 

[Randy Holmes-Farley]

If alk is where you want it, keep the same AFR dose.

 

[cjtabares]

If alk is where you want it, keep the same AFR dose.

Ok, thank you.