Very confused on params/test kits?

My big three as tested at 1.026 SG and 79*F:

Alk: 10 dKH
Calc: 460
Mag: 1600

I havent dosed anything in quite a while, in an effort to bring down the mag levels (raised to fight bryopsis). Despite this, over the last 5 months, mag has remained at 1600. Just decided to test my fresh SW made from Instant Ocean, and mag reads 1550. REALLY???

If anything I've read IO trends low on the big three, so now I'm placing my Red Sea Mag test kit on the watch list.

My real question is, why still the 460 reading for calc using API liquid tests?

Any thoughts to all this? Anything make sense?

 

what do you have in the tank in terms of livestock, that would utilise Calcium?
are you still doing water changes? as in many tanks that in itself maintains parameters, if there is limited demand

Magnesium
I have been measuring mine with a salifert kit and have determined that the actual utilisation over a 1 week period is so low, I cannot recognise it on the test kit LOL

I basically employed my spare dosing pump on my TM-01 for Vodka, simply becuase it seemed wasteful to use it for Mag as demand was so low

Steve

 

Not too much, a few LPS and SPS, but my 5% weekly WC keeps parameters stable to where I have not needed to dose.

This is why I'm guessing the test kit, because I cannot believe that IO is giving me 1600ppm mag. Mag has been testing 1600 since the beginning of April when I started testing for and boosting the mag.

 

Just doubled checked on another location
and Instant Ocean has been typically tested at 1350 Mag
so you may have either an exceptional salt mix, or a suspect test kit if your getting 1500 on a newly mixed bucket

are you sure the SG is correct in your mix? as if you have more salt in then that would also account for extra Ions in solution of which some are Magnesium

Steve

 

SG is kept and tested weekly (in both the DT and makeup water) at 1.026 via refractometer w/ 35ppt cal solution.

Keep asking questions, because I feel I've thought this through, but hoping someone can bring up something I haven't thought of.

The big question is why does my calc test in line with mag? If mag was off, I'd think the calc test would reflect that in a lower calc reading.

Most likely I'll have the LFS test my mag level, or purchase a second kit.

 

actually quite the opposite... this works out perfectly.
higher mag means higher of the other two that can be kept in concentration without precipitating. All will come down with time though

 

Are you just curious or worried about adverse effects of high mg? I don't believe the high mag would cause any problems. Please correct me if I'm wrong

 

Well, I took the opportunity to test the LFS's mag with my kit the other day, and it tested spot on 1350. So my mag kit isn't bad.

So, why am I getting 1600 from IO salt even before I add it to the tank? Just a wierd batch???

 

Because IO salt is designed to be used at around 1.021-1.022 (if I remember correctly as I haven't used IO salt in many years). Since you are keeping it at 1.026, you can expect that the Mag will be much higher than typical. 1.021-1.022 SG is 29-30 ppt. 1.026 is 35 ppt, which is 17% to 21% higher. So, 1300 Mag (just a random number I picked to illustrate my point) would then become 1516 to 1569 ppm.

 

Did not know that IO salt was designed for that SG. Seems kinda stupid they would aim for 1300 Mag at 1.022 SG... unnatural. Guess I'll be looking for a diffferent salt after this bucket is gone.