Magnesium Question ...

[Todd31]

Hello all...

I'm running a 29 gallon tank with 15 gallon sump. Well stocked with coral frags, no colonies however. Tank is 8 months old.

I recently noticed pale colored corals and saw that my alkalinity had dipped into the 6's. (Sidenote: Also stopped carbon and GFO because i believe my corals were being starved in a 0 nutrient system). So it was now time to start dosing. Raised the levels with BRS 2-part and then was going to see if i could keep stable levels with kalkwasser in the ATO.

Last week i monitored Ca/Alk/Mg daily to see what the story was. Red Sea Reef Foundation Test Kit.

Calcium fairly stable 450 ... But alk was all over the place. 9.65, 8.85, 8.7, 9.35, 9.0, 9.35, 8.7, 9.5. Not sure if its the test kit, my skills recognizing end color, or too much fluctuation of evaporation. Maybe a little of all of the above. Have a feeling i'm going to have to move to 2-part daily.

Here's the really weird thing. Magnesium fluctuation. 1500, 1420, 1560, 1520, 1460, 1320.

I was never dosing Magnesium so i think in theory it should only ever decline since i haven't done a water change right? Kalkwasser doesnt add Magnesium right?

Is the Red Sea test kit not a good one? The Magnesium one is the easy blue endpoint to recognize. Followed the directions, watched the youtube instructions.

Is there a time frame where the tank is "settling" and being erratic after raising my levels with 2 part and now using kalkwasser?

any thoughts would be great.... thanks.

--todd

 

[Justcause0_1]

Following

 

[sgdcover]

Did you ever get this figured out?

 

[BAD FISH]

There are mistakes that can be made when adding the triton in the test kit and fresh water top off / evaporatin will fluctuate your readings some 2 parts have trace elements including magnesium

 

[vio]

If i was u i will use ESV salt,Salifert tests, then 425 Calcium, 9 dKH 1325 Mag.

 

[sgdcover]

Interesting. I'm surprised to hear of the impact of evaporation. I've never seen that but I don't let the water change much. If it's absalifert test, shouldn't happen too often that mistakes are made. Mg in particular is hard to get to fluctuate. Good to know tho.

 

[BAD FISH]

well ive seen it before a kid was complaining his alk was at 16 and fish/corals where dying and wouldnt go down via dosing or wc. so he thought his test kits were wrong. I decided to take the trip bringing all my kits and i figured why not grab the refractometer too. after testing everything last being salinity turns out he was at 1.036 yet his hydrometer, you know the crappy plastic ones for a two or three dollars, was reading 1.026 we did a water change and slowly corrected the problem his alk was 12 lol

 

[Todd31]

Well.... I'm doing an upgrade this week into a 40 gallon so my demand should go down a bit temporarily with the added water volume. I just dont see how Magnesium should go up when im not dosing it and not doing a water change. I have a feeling my test kit is bad or its too easy to not be consistent reading the tests. I'm going to have the kalk offline for a few days once i get into the 40 and i'll do daily tests to try to get a grip on this again...i'll report back with results... thanks for input.

 

[Macropora]

What kind of gravel or sand are you using and are you taking the test results at the same time everyday? Also are you using any base rock? Some gravel and base rock has high magnesium content and could cause the levels to be higher depending on how much you use.

I would also pose your question in the chemistry forum for Boomer to answer.