Magnesium Levels (1 Viewer)

[texcoonazz]

My system is a BioCube 29. It is primarily set up for soft corals. Leathers, mushrooms, toadstool, hammer head, a closed brain and an open brain. And one lonely Bi Color Blenny named "Blenny Cravits". I have approx 20 lbs of live rock and the bottom is covered in 2 inches of crushed live coral.

Riddle me this....

My mag levels have consistently been in the 900 -1000 range since I set up my 29 gal Bio Cube. I do a 6 gallon water change weekly. All my other parameters are great. Nitrates are the only thing off 0 and it is only 5. My alk/dkh is 3+/8.5+. Calcium 460. I can control monitor and change almost everything with the smallest amount of additive. I have recently focused on getting my Mag up using Kent Tech M Magnesium. Like everything I started adding mag in lower than suggested amounts to see the effect. Dont want to shock things. I started at adding 2 tsp in AM and 2 in PM and saw a very little increase. Like from 960 to 1020 using ProfiTest. I increased little by little and am now up to 4 tsp in AM and 4 in PM and have not seen any increase over 1020. I have added in this manner for 3 days and notta.

If this keeps up the $15 bottle of Tech M MAG is not going to last.

So what the heck is going on here?

How can I get my Mag up if this is not working?

Thoughts?

 

[Slayer311]

I would try another test kit, I would be suspect of that low of mag numbers if your doing 6g water changes weekly.

 

[Rick]

+2 how old is your test kit

 

[texcoonazz]

I will check but think it is OLD.. Prob replace tomorrow then.

I found a Reef Calc and punched in my numbers and got an odd output.


I figure I have 20 gallons of actual water volume.
I punched in current level of 1020 ppm
Desired at 1300ppm
Using Kent Tech M

It is telling me to add...........

302.8 ml; 10.2 fl oz; 60.5 tsp
WTF..........

I cked double cked and triple cked with same result.


Calculator found at
http://home.comcast.net/~jdieck1/chemcalc.html

 

[thenewone]

i would recomen getting it from bulkreef and get a dosser its going to be cheaper in the long run

 

[Rick]

+1 gotta be your test kit.
I experienced the same thing this week.
Old test kit read 1150, new test kit showed 1550.

Good luck

 

[merkurmaniac]

I have had the same thing. Dunno how old my MG test kit is, but I was getting a reading of 700! The calculator on reef central told me I would need about 2 bottles of TechM Mag stuff. I probably need to get another test kit too. I had been dosing MG and now I get readings in the 1000 level, but I did not add anything like half a bottle. I am a little boggled by this. My Ca has been low though, more like 360 or so.

 

[Guest]

You know that reefcalculator is pretty well known and used. If it's telling you 61 tsp that may just be what you need.

Don't forget you are trying to increase levels by 280 ppm. I could imagine using an entire bottle of liquid caclium supplement to increase ca by 280 ppm.

 

[hoffy02]

I read something somewhere (LOL) that said that Mag levels were dependent on Cal and alkalinity... That you couldnt raise mag unless the others were raised with it? I dont know but something to check into

 

[texcoonazz]

You know that reefcalculator is pretty well known and used. If it's telling you 61 tsp that may just be what you need.

Don't forget you are trying to increase levels by 280 ppm. I could imagine using an entire bottle of liquid caclium supplement to increase ca by 280 ppm.

Good thing I am dealing with my 29 gallon bio and not my 100 gallon tank. If this is the case it could break my bank getting the numbers up in it. Think I will keep it FOWLR.

 

[Guest]

You should try a solid magnesium supplement, they are much more concentrated. Same thing for calcium and alkalinity.

 

[nicky]

definitely check the test kit. in my 50 gal. it takes approx 270 ml or 9.1 fl oz to raise it by 100. used the reef chemistry cal. and raise no more than 100 at a time.

 

[CBBSteve]

Hi, txcoonazz.
Epsom Salts is a very cheap alternative for getting your magnesium level up. I've used it for years...

You might want to check the magnesium level of your salt mix, most salts are usually on the low side. I add mag (ca and alk also) to my make up water before doing a water change.

Also, it seems that your calcium and alkalinity are out of balance. For a ca level of 460, your alk should be at 4.95 meq/l. Check this article:

http://www.reefkeeping.com/issues/2002-04/rhf/feature/index.php

and this one:
http://www.advancedaquarist.com/issues/nov2002/chem.htm

good luck,
Steve

 

[Guest]

hoffy02, you have it the other way around. Because magnesium hinders the precipitation of calcium carbonate, you can't raise your calcium and alkalinity beyond a certain threshhold when magnesium is low.

 

[texcoonazz]

Thanks for all the input and help.

I read thru the articles once and need to give my brain a chance to absorb and give it a second read.

Looks like I need to work my ALK up a little....

Then pick up a new test kit for my Mag and pick up a solid mag supplement. I use solids for my Alk and Calcium. Works good there. Stands to reason I should go that direction with the Mag.