Parameters of Instant ocean reef crystals

[Kait_DeBoer]

Myself and my LFS have been having a problem with reef crystals mag being low. Fresh batch at 1.026 was testing 1200 for my box and my lfs.

Contacted spectrum brands and they are making it right. I also sent them a sample of the water and a sample of the salt I was having a problem with.

Omg! All summer long I had issues with my magnesium dropping after water changes. This must be why! This caused huge problems in my tank because my calcium and mag was in one solution. I have since switched over to fauna Marin balling salts and do a 3 part dose!

 

[brclark82]

My current bucket of Instant Ocean (not reef crystals) which was purchased in March of this year is mixing low Mag too

11.0 dKH, Mag- 1200, Cal- 380

I bought some Magnesium supplement so I don’t have to throw it out and holy cow you’ve gotta use a lot of Magnesion to raise it from 1200 to 1350

 

[Cichlid Dad]

My current bucket of Instant Ocean (not reef crystals) which was purchased in March of this year is mixing low Mag too

11.0 dKH, Mag- 1200, Cal- 380

I bought some Magnesium supplement so I don’t have to throw it out and holy cow you’ve gotta use a lot of Magnesion to raise it from 1200 to 1350

+1. I always test and make adjustments as needed. I'm seeing 1200 mag 11 alk 460 cal using salifert in my current bucket.

 

[Randy Holmes-Farley]

My current bucket of Instant Ocean (not reef crystals) which was purchased in March of this year is mixing low Mag too

11.0 dKH, Mag- 1200, Cal- 380

I bought some Magnesium supplement so I don’t have to throw it out and holy cow you’ve gotta use a lot of Magnesion to raise it from 1200 to 1350

At what salinity?

 

[Randy Holmes-Farley]

+1. I always test and make adjustments as needed. I'm seeing 1200 mag 11 alk 460 cal using salifert in my current bucket.

At what salinity?

 

[Cichlid Dad]

At what salinity?

1.025 . refractometer calibrated with commercial solution

 

[Jedi1199]

This might prove to be an interesting experiment? One of the big "knocks" on IORC is the brown precip that builds in the mixing container.

Since (I assume) we all start with clean RODI water and dry salt, what exactly does that brown gunk contain?

It stands to reason that SOMETHING from the salt is what makes up that sludge.. What exactly is it that is lost there?

I try to mix the salt the day before I use it, or the day of use, but life doesn't always work on my schedule so I often have a batch sit for a week or so..

Testing a brand new batch and a week old batch might shed some light on what is lost and how fast....??

 

[Randy Holmes-Farley]

1.025 . refractometer calibrated with commercial solution

So that's part of the problem and the reason I asked.

I do not know if your kit is accurate or not, because magnesium testing is among the least accurate of the kits we use, but using a lower than normal ocean salinity will give a lower than normal ocean magnesium level.

If you raised that salinity to the ocean average of 35 ppt, your 1200 ppm becomes 1267 ppm, which is indistinguishable from the ocean average of 1280 ppm.

Given the likely uncertainty in both your salinity measurement and the magnesium measurement, I'd suggest there may not actually be a magnesium issue.

 

[Randy Holmes-Farley]

This might prove to be an interesting experiment? One of the big "knocks" on IORC is the brown precip that builds in the mixing container.

Since (I assume) we all start with clean RODI water and dry salt, what exactly does that brown gunk contain?

It stands to reason that SOMETHING from the salt is what makes up that sludge.. What exactly is it that is lost there?

I try to mix the salt the day before I use it, or the day of use, but life doesn't always work on my schedule so I often have a batch sit for a week or so..

Testing a brand new batch and a week old batch might shed some light on what is lost and how fast....??

Normal IO and other high alk mixes mostly precipitate calcium carbonate.

The off brown gunk in RC IMO, may relate to the vitamins added and bacteria action on them (since it is not present in normal IO).

 

[Cichlid Dad]

So that's part of the problem and the reason I asked.

I do not know if your kit is accurate or not, because magnesium testing is among the least accurate of the kits we use, but using a lower than normal ocean salinity will give a lower than normal ocean magnesium level.

If you raised that salinity to the ocean average of 35 ppt, your 1200 ppm becomes 1267 ppm, which is indistinguishable from the ocean average of 1280 ppm.

Given the likely uncertainty in both your salinity measurement and the magnesium measurement, I'd suggest there may not actually be a magnesium issue.

Morning, what method have you found to best measure mag?

 

[Randy Holmes-Farley]

Morning, what method have you found to best measure mag?

Well, I'm on the fence of whether it is even worth measuring at all since there are so many off results and folks react to them in negative ways.

Even ICP has an uncertainty of at least +/- 5%, or about +/- 64 ppm (shown by sending samples to multiple vendors and comparing the values).

I do not recommend folks try to interpret absolute magnesium values to high precision for this reason.

Based on user comments and not careful analysis, I'd probably recommend the Salifert magnesium kit, and interpret the values to +/- 50 ppm.

 

[brclark82]

At what salinity?

1.0255 measured with tropic Marin hydrometer and my Salifert test kit measured 1180 so I ordered a Red Sea test kit thinking maybe the Salifert was incorrect and it got the 1200 I posted

 

[Randy Holmes-Farley]

1.0255 measured with tropic Marin hydrometer and my Salifert test kit measured 1180 so I ordered a Red Sea test kit thinking maybe the Salifert was incorrect and it got the 1200 I posted

Same answer as above. I'd raise the salinity. Boosting magnesium may also be a fine plan since exact values are unimportant, IMO.

 

[Brian1f1]

I/O RC alkalinity is 13!?!?

Appears so! I'm surprised too. Actually found this trying to figure out why my all won't drop below 13.... now I know.... Is this a good thing or only good for SPS or what?