2 Part Dosing

[Wretch]

Just want to check my numbers here. I am going to be mixing my solutions in 2 litre jugs. So all my ingredients are cut in half.

Calcium - 1 cup Anhydrous Calcium Chloride
Alkalinity - 1 cup Sodium Carbonate
Magnesium - 2.5 cup Magnesium Chloride 1.5 cups Magnesium Sulfate or 4 cups Magnesium sulfate

As for the Magnesium solution is one mix better then the other?

Thanks.

[nerdz]

I can't verify the quantities right now... But as for the magnesium, most people use the one with two ingredients. That all sulfate recipie would only be a minor concern if you never did water changes as sulfate levels would rise. Sulfate is still a major portion of the 2 mag recipe anyway

[mark]

RHF recipe (http://www.reefkeeping.com/issues/2006-02/rhf/)

[Wretch]

RHF recipe (http://www.reefkeeping.com/issues/2006-02/rhf/)

Thanks for the info.

[Wretch]

Ok got my doser setup to dose Calcium and Alkalinity but have a question about magnesium. J&L sell Magnesium Chloride or Magnesium Chloride Flake. The two are the same thing just in different form, so why is here a price difference between the two? Do you have to weigh the flake? or can it be measured? Does the flake dissolve as well as the powder? Is the price difference worth it? Thanks all.

[hillegom]

When you get the mag chloride, get some mag sulphate (epsom salt) from costco. Its the cheapest. Mix as in the given recipe above.
Sorry, I don't know the difference betw. the powder and the flake.

[Myka]

A certain mixture of magnesium chloride and magnesium sulfate has no net effect on seawater's major anions (chloride and sulfate). All that is necessary for such a recipe is to add these two ingredients in such a ratio that they add chloride and sulfate in the ratio naturally present in seawater (which is 7.1 to 1 on a weight basis and 9.6 to 1 on a per ion basis).

To perfect such a recipe, it's imperative to know the amounts of sulfate in Epsom salts (39%), the amount of chloride in magnesium chloride hexahydrate (34.9%), and their bulk densities, because most aquarists will use a volume based measurement (1.05 g/cm3 for Epsom salts and 0.85 g/cm3 for magnesium chloride hexahydrate solids). Taking all these factors into account, the desired volume ratio is 10:1, MAG flake to Epsom salts, as a supplement; for instance, 10 cups MAG flake and 1 cup Epsom salts.

http://reefkeeping.com/issues/2006-07/rhf/index.php

RHF wrote this article when calcium reactors were THE thing. 2-part dosing is more common now though, and we add a lot more chloride ions through calcium choride, so a better version for 2-part particularly if you are dosing calcium chloride heavily is 5:3 chloride to sulfate to make up for all the chloride we're adding via 2-part.

[hillegom]

I use this recipe from Randy Holmes:

3. Using both Epsom salts and MAG flake, dissolve 7¼ cups MAG flake and ¾ cup Epsom salts in one gallon of water, and use that to supplement magnesium in amounts determined using this linked online calculator, with the entry "Randy's Recipes 1 and 2 Versions A and B," and ignore for this purpose what those designations mean. This recipe is preferred, but its advantage over recipe #2 is minimal in most cases.

Which is derived from:
http://reefkeeping.com/issues/2006-07/rhf/

[reefwars]

which like mindy said is 10yrs old now:)

[reefwars]

oh and flake is most likely dihydrate fwiw:)

[Myka]

oh and flake is most likely dihydrate fwiw:)

Oh ya, that ^ too. :lol:

[Wretch]

What is the difference between hexahydrate and dihydrate?

[Myka]

What is the difference between hexahydrate and dihydrate?

4 water molecules. :D It's how much water is contained within the compound.

[Wretch]

4 water molecules. :D It's how much water is contained within the compound.

Ok so if you need 5 cups of hexahydrate how many cups of dihydrate would be needed?

[gregzz4]

I use this recipe from Randy Holmes:

3. Using both Epsom salts and MAG flake, dissolve 7¼ cups MAG flake and ¾ cup Epsom salts in one gallon of water
Deitmar, why are you using the recipe #1 Part 3B measurements ?
I use the Part 3A dosing with 5 cups and 3 cups

An Improved Do-it-Yourself Two-Part
Calcium and Alkalinity Supplement System (http://reefkeeping.com/issues/2006-02/rhf/index.php)

[hillegom]

I don't know Greg, I have been using that for a long time. Whats wrong with that recipe?

[hillegom]

ok, I looked up #1 3B
Thats not what I am using, that one is all epsom salts. (mag sulphate)
I use 7.25 cups mag chloride to .75 cups mag sulphate to one US gal.

[gregzz4]

Nothing wrong with it that I know of. Just curious. Seems like such a small amount of sulphate to chloride.

I just looked at your link and see that it's his first/original recipe.

[hillegom]

I see the error in my ways.
Mark in post #3 posted Randy's second, revised version of DIY supplements which advocates 5:3 as Mindy is suggesting. Mag chloride:mag sulphate
The next batch of Magnesium I mix up will be that ratio.

[Wretch]

ok, I looked up #1 3B
Thats not what I am using, that one is all epsom salts. (mag sulphate)
I use 7.25 cups mag chloride to .75 cups mag sulphate to one US gal.

I just bought some J&L shlobster magnesium chloride and on the back that is the recipe given to mix your magnesium.

[Wretch]

Ok so according to J&L the powdered magnesium chloride and the flaked magnesium chloride are the same thing. Bought the flaked stuff and it dissolves fine and what not but was a pain in the butt to get flakes small enough to fit into the jugs small opening.

[Wretch]

Ok still need a little help. My calcium is at 450 my alk is at 8 and magnesium is at 1350.

After checking my alk every day it turns out I am using .3 dkh every day. So according to the 2 part calculator I need to add 12ml a day of alk solution.

My only question is about water changes. I have about 55g of water in my system and do 5g water changes once a week. My salt usually mixes up around 10dkh. So what is the best way to keep alk at 8?

Should I dose a little less then needed so when I do my water changes it brings it back to 8?

[reefwars]

You can dose less on waterchange day , a small water change even in higher alk isn't going to effect it to much and you can always control the amount of alk that's added be it what you daily dose or the salt mix it's self can be manipulated for more or less.