Need Advice With Calcium And Magnesium Suppliments

[idlefingers]

I got calcium and magnesium test kits the other day and was surprised to find my calc and mg levels a little on the low side. Here's all the results:

• SG 1.024
• PH 8.4
• Ammonia 0
• Nitrite 0
• Nitrate 0
• Phosphate 0 - 0.25
• Alk 9.6dKH
• Ca 370ppm
• Mg 1050ppm

I was thinking of getting some Seachem Reef Adv Calcium and Magnesium to try to increase those levels a bit and was wondering if anyone has any alternate suggestions or whether that's a good idea?

Also, I was looking at Seachem's dosage calculator on their website and according to it, I'll need to add 625g of magnesium powder to get the mg from 1050 to 1300ppm.. That's more than an entire pot of the stuff! Is it true I'm gonna need that much or could there be an error with their calculator?

Finally, if I do get both those, would it be okay to make a mix with both of them in the same container and then drip that into the tank over a period of time so it doesn't go in too fast?

Thanks for any advice!

 

[AK77]

That is a little bit on the low side with regard to the calcium. What is your sand bed? Is it aragonite sand or similar calcium carbonate based substrate?

 

[idlefingers]

it's aragonite sand (not the live stuff)

 

[SkiFletch]

Well Idlefingers, what you need is a bulk/industrial supply of Magnesium Chloride and Magnesium Sulfate but I can't be much of help to tell you where to look over there. MgCl is commonly sold in the States as a driveway De-Icer in the winter time and MgSO4 is commonly sold as "Epsom Salts" in drug stores for use as a household cleaner/remedy (apparently commonly used by my grandparents ).

As for Calcium, you can use Calcium Chloride which is another common driveway De-Icer sold here in the States.

Have you read through Randy Holmes-Farley's 2-part additive system for upkeep of calc/alk/mg? If not, go to the realm of knowledge sticky, page 2, I've linked it there

 

[idlefingers]

Cheers ski! I have no idea where I'd be able to get calcium chloride and magnesium chloride over here, but I'll have a look around. It was nigh impossible to find ammonia in this neck of the woods when I was wanting to cycle a FW tank. So if that's anything to go by, it's going to be hard to find.

In the meantime, assuming I cant find those things and cost aside, would those seachem alternatives do the same job?

 

[Musho3210]

yes, you can make your own two part for a lot cheaper than commercially available ones (darn you kent)

You can also buy bulk amounts of other things at this place: (as well as buying the MYO two part ingrediants)

http/www.twopartsolution.com/

 

[SkiFletch]

Even if they offered it, something tells me that internationasl shipping might be a little prohibitive

 

[idlefingers]

I don't really want to buy in bulk right now and for the time being am not really that bothered about paying a little more and buying it pre-mixed while I get going and get the hang of everything. I just want to make sure I do it right and don't over do it with anything.

Also, will supplementing Ca and Mg cause any other elements to lower as a result?

 

[Musho3210]

oh sorry, i didnt notice you were in the UK

 

[SkiFletch]

Also, will supplementing Ca and Mg cause any other elements to lower as a result?

Heh, it depends... The problem is that calcium and alkalinity can form calcium carbonate if one is supersaturated in relation to the other. I'll use yours as an example. You have higher alkalinity 9.7dKH, a lower calcium of 370ppm, and a very low magnesium. The presence of high magnesium inhibits the random reaction of calcium and carbonate ions to form the calcium cabonate salt. But since your tank has low magnesium, that reaction is energetically favorable to be possible if the right conditions exhist.

If you were to say dump 4 cups of caclcium chloride additive (or a commercial equivalent) into your system all at once you would locally supersaturate with calcium right where the addition took place. Now because there was a high source of carbonate (alkalinity) allready present and because you have lower magnesium, you have just created an energetically favorable situation for the formation of calcium carbonate compounds and it will happen right before your eyes. Usually the water will turn cloudy within seconds-minutes as the supersaturated calcium bonds with the carbonate to create tiny little molecules of the solid salt that float around the tank creating the "cloudy" appearance.

You can avoid this reaction in one of 3 ways. Pour the additive in slowly and spread it around in the tank so that it can diffuse into the water column. Pour it directly into the inlet of a pump/powerhead again to increase diffusion. Or bring up your Magnesium so that it's not a problem.

Just keep in mind that the reverse can be true if you have low alkalinity and high calcium . Hope that chemistry lesson in 5 seconds or less made sense

 

[idlefingers]

I had to read it a couple of times (chemistry isn't my strong point), but it makes perfect sense! Thanks for explaining it So I'd be safest if I got the magnesium up before dosing the calcium.. but is the calc reading of 370 too low to wait?

 

[SkiFletch]

Try to shoot for like 450ppm. you've got a big tank so you can dose say 1/2 a cup to a cup per day. just make sure you spread it out

Edit: and keep an eye on alkalinity and don't let it drop too low

 

[Musho3210]

kalkwasser is an easy way (but be careful, lots of people make mistakes using kalkwasser and get a tank crash) to get an even amount of both alkalinity and calcium, but wont help magnesium.

 

[SkiFletch]

Agreed, and remember, you CAN NOT dose kalkwasser at a high rate, else you'll SKYROCKET your pH. Kalkwasser pretty much has to be dripped

 

[Musho3210]

kalkwasser has a ph of 12 i think