DIY Red Sea Salt? Possible?

[vahegan]

What is Seawater? by Randy Holmes-Farley - Reefkeeping.com

An Artificial Seawater Recipe
For those who are interested, the following artificial seawater recipe is taken from "Chemical Oceanography" by Frank Millero. It makes a recipe that matches 35 ppt seawater in terms of major ions, but does not try to match all minor and trace elements, most of which will be present as impurities in the major elements.

23.98 g sodium chloride
5.029 g magnesium chloride
4.01 g sodium sulfate
1.14 g calcium chloride
0.699 g potassium chloride
0.172 g sodium bicarbonate
0.100 g potassium bromide
0.0254 g boric acid
0.0143 g strontium chloride
0.0029 g sodium fluoride
Water to 1 kg total weight.

When I was starting in the marine hobby, you couldn't easily buy proper salt mixes in my country, and I decided to come up with my own recipe. I took the element composition of natural seawater, then used Excel to combine various salts, their adjusting proportions until I got as close to NSW, as possible. Note that it is difficult to make a salt mix in a way that calcium carbonate would not precipitate, therefore I was making saltwater. I first mixed the following salts (the amounts are in grams, per 100 liters of water):

NaCl	2719​
MgSO4*7H2O	693​
MgCI2 * 6Н20	599​
KCl	74​
NaHCO3	20​
KBr	10​
Н3ВО3	1.5​
LiF	0.2​

And then I dissolved calcium and strontium chlorides separately and slowly added in the flow:

CaCI2 * 2Н20	161​
SrCI2 * 6Н20	4.0​

The most difficult part were the microelements. I made a concentrate, that I was adding as 1ml per 100 liters. The following are in milligrams per 100 liters:

FeSO4*7H20	4.8783704​
C12H22FeO14	7.82860086​
CuSO4*5H20	0.11787112​
NiSO4*5H20	6.25545733​
ZnSO4 * 7H20	4.70632061​
MnSO4 * H20	0.70757927​
Na2MoO4 2H2O	2.10338603​
CoSO4 * 7H20	0.19078455​
KI	7.84879433​

For some 5 years, I kept fish and even corals (mostly softies) using my homemade saltwater. After some time, I have adjusted the recipe to make two concentrated solutions:

А
NaCl	1320​
MgSO4 * 7H2O	700​
NaHCO3	20​
H3BO3	1.5​

B
NaCl	1400​
MgCl2 * 6H2O	500​
KCl	14​
KBr	10​
CaCl2 * 2H2O	155​
SrCl2 * 6H2O	4​

I would dissolve the salts in list A and B in 10 liters of water each. The would use equal amounts of solution A and solution B to mix with RO water and produce the desired amount of saltwater. So, by using 1 liter of A, 1 liter of B and 8 liters of RO water, I'd get 10 liters of saltwater.

These were good old times, 11 years from now. The mix was cheap and the results were good, I also shared my mix with friends...

P.S. must have been more than 11 years, but the oldest version of my spreadsheet I could find in the archives is dated 2012...

 

[Randy Holmes-Farley]

Thanks for posting the recipe!

 

[Aquarist76]

Never had a Problem with Reef Crystals, nor finding decent prices on it. When I get to the bottom of one Bucket, or the last bag, and before I get into the unopened new container. I start looking around for the best deal. Never very far into that bucket or box of salt, when I have more salt on hand.

Even prices on Reef Crystals have doubled lately. Used to be able to get it for $30-40 a bucket and now lucky to get it for $60-70 a bucket.

I used to use Red Sea but then switched to Liveaquaria salt back when they had coupons it was cheaper. The last couple years as coupons have dried up I switched to Reef Crystals. MSRP is now $99/bucket for that. Crazy!!!

I'd LOVE a solution for cheaper salt. I run over 400G between various tanks and do daily auto water changes.

 

[vahegan]

Thanks for posting the recipe!

It was huge fun! Had to do a lot of DIY. Even for sand, I couldn't source aragonite, so had to crush bits of marble using hammer, followed by a sieve to make sure it was the size of fine salt grain. Took me a couple of weeks to finish the endeavor Hard to imagine the trepidation (and following elation upon success) when I let my first blue devil in my DIY water. I didn't know at the time, THAT would live in anything, lol.