Magnesium Levels in the tank

[Sea Turtle]

Hi everyone,

I have noticed that my Magnesium level is a little low 1300 which I think is making it difficult to maintain proper calciuma and alkalinity levels. How do I add magnesium to the tank affectively. I am currently using the B-ionic 2 part soluion with the LiterMeter III. I aslo have the third pump dosing the top off water so dosing magnesium is out of the question. I really want to know what product I need to use and how to do it. Also, can I just add that or do you have to add something else at the same time and amount? Does it have to be dosed or can you just add a couple of cap fulls ever so often?

Thanks.

 

[iseeweed]

I am sold on twopartsolution.com. They sell bulk magnesium chloride, and magnesium sulfate. I hand dose 4oz a day in my 75g and the mg level is usually around 1400ppm. The only thing that I dont like is the solution settles, so you have to shake it before adding.
Your 1300 sounds pretty good to me though. What are your alk and ca levels?

 

[Sea Turtle]

My calcium level is about 300 to 330 and alk I have to admit I don't know because I recently ran out of testing solution. I have to believe that it is around 7 to 10. it has always been there.

 

[iseeweed]

What is your salinity?

 

[Ben1]

I am also using the bulk reef supply mix of magnesium and it works for me. If you are using a calcium reactor you can add Zeomag to the reactor to keep magnesium up or dolomite.

 

[chris&barb]

1300ppm Mg is not to low, NSW levels are about 1250ppm, you are right on target.

Your other post about the "tan cement" is why you cant keep Ca levels up. It sounds like you are adding your Ca and Alk supplements too fast and they are precipitating out. You need to dilute these supplements in RO water and drip them slowly.

 

[kgross]

1300 is not to low, myself I would not worry about it.

Now 300 for calcium is very low for a reef tank sounds like you need to increase the amount of the b-ionic you are dosing.

Kim

 

[Sea Turtle]

Thank.

I think that I might be adding to much alkalinity which is lowering the calcium.

 

[kgross]

If you are dosing B-ionic you should be dosing the same amount of ca and Alk so you should not be having a problem with the Ca dropping.

I just released you have 2 threads with the same problem going.

Again, before you can solve your problems you need to have a correct value for your Ca, Alk and Mag. B-ionic should keep your Ca and Alk close to in balance, so unless you ALK is way high, which it might be, you should not be having a major problem with precipitation (ppt). But if you have a bad test kit or 2 you could have much higher alk which can cause CaCO3 to ppt and cause your calcium to drop lower.

Kim

 

[Sea Turtle]

Ok. I'll stop at the lfs tonight on my way home from work and get an dKH test kit. Then we go from there.

Thanks for your help.

-Sea Turtle

 

[kgross]

Try to see if they can check your Ca as well. Or if you can't take your water in since you are at work, see if you can get a sample of there water with a known ca level to test. Just want to make sure your reading is correct,

Kim

 

[Sea Turtle]

Okay. I'll test all three tonight and get some acurate numbers and post them tomorrow. I know we can get this fixed.

I know this si stupid question, but how much do you think that this would affect the growth of your corals? Mine seem to be growing very slowly and I wonder if this could have a lot o do with it.

 

[kgross]

If your Ca is really at 300 it will effect your corals a lot (stonies).

I think this could be a big reason for the problems. Once you get good measurements post them and we can figure out what to do to get things figured out. Also what do you do for water changes, and what salt mix are you using and what salinity do you keep your tank at, and how do you measure (is it properly calibrated)?

Kim

 

[Sea Turtle]

I use intant ocean sea salt. I change out 2.5 gallons every 2 days. That way I don't have the heavy buckets and it is much easier. Doesn't change the temp of the tank.

I use and instant ocean hydrometer. I keep the salinity at 1.026

 

[kgross]

IO is normally pretty low on Ca/Alk and Mag, but you are changing a pretty small amount so it should not cause any problems. Have you calibrated your hydrometer at all? If it is the swing arm one it could be off as much as .003 out of the box.

Kim

 

[Sea Turtle]

Yes, I do have the swing arm one and no, I have never calibrated it. Everything has always seemed good as far as alkalinity so I have never really felt I needed to. I think that I need to buy a refractometer. After Christmas I will buy one. Are the swing arm models ok to use?

 

[kgross]

I will say the swing arm units are fine to use, but you need to calibrate them some how. They can be way off, but if you keep them clean they are normally very repeatable.

Kim

 

[Sea Turtle]

How would I calibrate something like that?

 

[kgross]

The simplest way is to measure a known water sample. Find somebody with a calibrated refractometer and have them measure your tank and compare, or you measure there tank and compare. If you find out your swing arm is say .002 low, you know when it says 1.027 you are really at 1.025 or very close to that.

Kim

 

[Sea Turtle]

Thanks. Sounds simple enough. I guess that I should probably just go out and buy a refractometer. Any advice as to which model I should get?

I really like the swing arm becasue it is quick. I have the feeling that a refroctometer is not a quick test?