Raising Magnesium w/ Seachem Crystals

[tutmatt3]

Hey guys, so MG is testing ~1240-1260
I tested my IO water, and that is testing 1170 @ 1.026
Bad batch? Am I doing something wrong here?
Mixing ~ 4.75gallon water w/ 2.5 cups IO & an extra 3tblspoons to achieve 1.026

Question 1) To raise my tank to ~1350:
Is Seachem Reef Advantage balanced to use w/ the B-Ionic dosing?
http://www.seachem.com/reef-adv-magnesium.php
If my calculations are correct, to increase 50gallon of water by 100ppm MG w/ this product, I would need ~238g - or 47tsp - or ~16 tbl
The product claims to raise 5ppm per 80l (21gal) for every 5grams
How fast should I increase MG? 25ppm per day okay?


Question 2) I'll be frequently testing freshly made water for future water changes, but if they keep reading low, should I also prep that w/ mag? Or will B-Ionic now control the tank, even if I do water changes w/ low-mag salt

Readings were taken w/ a Salifert Test kit, 2-3 times, @ 1.026
I tested calcium too of the freshly made water, and it read 390, so that helps me confirm salinity is definitely in the right area.

I also have Reef Crystals which I don't use, wondering if it's better to mix the two instead of pre-dosing the Water? idk, too many options -___-
Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

Normal IO is supposed to read higher. Lots of things could be off: batch of salt, test kit, salinity measurement, etc.

 

[Randy Holmes-Farley Verified Community Expert]

The Seachem product is fine to use to raise it, assuming it really is low.

 

[tutmatt3]

Yeah that's why I've been trying to retest & calibrate my equipment as much as possible.
When I first used IO (same test kit) it was reading good. 1300s
Reef Crystals was high 1300s when I was using it

But with this new box, this is the first time I've been testing, and reading things this low. I'm going to assume it's a badbatch, but will test the rest of the bags as well when I get to them.

Lets cross fingers that there's no issues w/ seachem this time

-----
Do my calculations look correct?

If my tank needs 16x tablespoons total to get it to 1350ish, would dosing 4x tablespoons a day (premixed in RODI) be sufficient?
I'll be sure to offset this from b-ionic dosing, either different days or mid-day

 

[Randy Holmes-Farley Verified Community Expert]

Use this calculator for dosing (or their calculator):

http://reef.diesyst.com/chemcalc/chem_calc3.html

in this one, use the entry for magnesium chloride hexahydrate.

 

[tutmatt3]

Understood. Just retested fresh mixed water - 1190

Their calculations give me:
~238g - or 47tsp - or ~16 tbl

The website gives me:
~157g / 37.5 tsp / 12tbl

I'll play it safe, and use the lower numbers, and retest everyday to see what I get. I'll start today w/ 3x table spoons

Thanks again Randy - will report back!

 

[tutmatt3]

How cool, came up w/ my numbers on my own earlier, and turns out they have a calculator.
Glad to know I was pretty dang close

Interesting that so far I added in 3TBlspoon (9tsp) mixed w/ RODI over over 6x hours ago, and readings are still the same.. 1240.
I know the 3TBL dose = ~20ppm, so maybe that is the test range of accuracy then

------
E: Looks like their note says not to raise the mag over ~25ppm per day. Guess 3TBL will be my daily dose until I get my desired amount.

 

[Randy Holmes-Farley Verified Community Expert]

I suspect you just cannot accurately detect a 20 ppm change.

 

[tutmatt3]

Normal IO is supposed to read higher. Lots of things could be off: batch of salt, test kit, salinity measurement, etc.

For what it's worth I tested another bag from the same box which I would assume to be the same batch and it says it 1300 magnesium and 425 calcium

Moving forward in the future will it be safe to test each bag once and assume the rest of the contents should be very similar to those results?

Wpuld help prevent me from testing each and every single water change bucket

 

[tutmatt3]

For what it's worth I tested another bag from the same box which I would assume to be the same batch and it says it 1300 magnesium and 425 calcium

Moving forward in the future will it be safe to test each bag once and assume the rest of the contents should be very similar to those results?

Wpuld help prevent me from testing each and every single water change bucket

Take it back. That's at 1.028-29.
Apologies

 

[chipmunkofdoom2]

For what it's worth I tested another bag from the same box which I would assume to be the same batch and it says it 1300 magnesium and 425 calcium

Moving forward in the future will it be safe to test each bag once and assume the rest of the contents should be very similar to those results?

Wpuld help prevent me from testing each and every single water change bucket

My experience mirrors Randy's. I tested every batch of saltwater I made for a very long time. For me Instant Ocean had relatively high magnesium, close to 1,400ppm. I did every once in a while receive a box that had inexplicably low magnesium, around 1,200ppm. The norm was close to 1,400 though.

Additionally, each bag was very consistent. If the magnesium was low, all 4 bags were low. If the magnesium was high, each bag was high. The calcium and carbonate were consistent across bags as well.

 

[tutmatt3]

My experience mirrors Randy's. I tested every batch of saltwater I made for a very long time. For me Instant Ocean had relatively high magnesium, close to 1,400ppm. I did every once in a while receive a box that had inexplicably low magnesium, around 1,200ppm. The norm was close to 1,400 though.

Additionally, each bag was very consistent. If the magnesium was low, all 4 bags were low. If the magnesium was high, each bag was high.

Yeah I got in contact w/ IO, and they said it could most likely be a bad batch, & are sending over a new box. Great customer service
I do feel confident w/ my testing that this indeed is a bad batch, and that it took me raising salinity to 1.029 to get desired levels.

Will report back once the new box comes in!

Random question for u pros
If salts like IO have good parameters at 1.026salinity, (ca/mg/etc), why do some reefers decide to run slightly lower, 1.025, 1.024, and instead have to raise these elements manually?
Any benefit?

 

[Brew12]

Yeah I got in contact w/ IO, and they said it could most likely be a bad batch, & are sending over a new box. Great customer service
I do feel confident w/ my testing that this indeed is a bad batch, and that it took me raising salinity to 1.029 to get desired levels.

Will report back once the new box comes in!

Random question for u pros
If salts like IO have good parameters at 1.026salinity, (ca/mg/etc), why do some reefers decide to run slightly lower, 1.025, 1.024, and instead have to raise these elements manually?
Any benefit?

I find IO to have higher parameters than I am looking for but need additives to maintain Alk and Calc between water changes.

 

[tutmatt3]

I find IO to have higher parameters than I am looking for but need additives to maintain Alk and Calc between water changes.

So what do you run yours at? And which parameters in particular are you referencing?

 

[Brew12]

So what do you run yours at? And which parameters in particular are you referencing?

I am still working at locking things in. I'm way too much of a tinkerer for this hobby. Recently switched from Reef Crystals to regular IO and going to try something with lower numbers next. I've decided I want to maintain Alk between 8 and 9, with Calc 430-440. I'm good with mag around 1400. I keep my salinity between 1.025 and 1.026.

 

[tutmatt3]

I am still working at locking things in. I'm way too much of a tinkerer for this hobby. Recently switched from Reef Crystals to regular IO and going to try something with lower numbers next. I've decided I want to maintain Alk between 8 and 9, with Calc 430-440. I'm good with mag around 1400. I keep my salinity between 1.025 and 1.026.

Hah, I did the same thing too.
Had IO first month, switched to RC, then back to IO

Just this IO box of course was an off batch, but I can tell my tank def enjoys it more. =)

 

[tutmatt3]

The Seachem product is fine to use to raise it, assuming it really is low.

By the way - got in contact w/ IO, and they sent out a new box. Tested them side by side, and I did indeed have a bad batch.

The new box came in @ 420 calcium, 1300 mag. I guess I'll just test each box once to ensure the batch is @ standard =)

 

[Randy Holmes-Farley Verified Community Expert]

Glad they replaced it for you.