melev

I got two more tests done today. Calcium is 450ppm, Magnesium is 1300ppm. I prefer Magnesium to be higher, more like 1400ppm.

My reef has a liquid volume of 450g including the sump volume and satellite tanks.

I took a graduated 8oz cup to measure solution into a plastic jug (formerly a pretzel container), and 15 of those cups filled it up. That's 120 oz.

The recommended recipe is 10 grams per 8 oz (or 2 tsp per 8 oz) of water, I determined I'd need 30 teaspoons for the batch. Googling told me there are 3 teaspoons per tablespoon, so I used 10 tablespoons for 120 oz. Each scoop that was added to the RO/DI water had a chemical reaction that briefly sounded like fire erupting. I was careful to add it safely and not get spattered. The container itself got a little bit warm, but not hot as I'd expected.

What I really appreciate is that I only used a small fraction of Magnesium Pronto compared to what I used to use (Randy Holmes-Farley's Recipe #2: 8 cups of two types of magnesium powders added to 1 gallon of RO/DI).

If my math is right, it would take 900 tsp to bring up 450 gal of water 125ppm higher. There are 768 tsp in a gallon, and I have less than a gallon mixed up (120 oz versus 128 oz). That's 720 tsp worth. Adding that much will probably bring the reef's magnesium level up 100ppm overall. (Per the instructions, 10ml or 2 tsp will bring up 1 gallon by 125ppm) I do have an email to Two Little Fishies to verify my calculations, and will update this blog if anything is incorrect.

Based on how much I used from the 1kg container, it appears I can probably mix up 5 of these containers if I use the same ratio each time.

Over the years, I normally had to dose Magnesium quarterly if that. Once it is up, it takes a long time to deplete. From 2011-2013, the salt mix I used had such high Magnesium in every bag that I never had to dose it once in almost three years. I know that Montipora capricornis loves Magnesium and my reef has about 6 different healthy "caps", which gives me a visual indicator if the Magnesium is sufficient presently. This one looks very happy.



This is the second gallon of Magnesium I'm adding to my reef this year. Like I mentioned, it lasts a long time.

UPDATE (5:31 pm CST):
After talking to Julian Sprung to confirm my numbers, a decimal point was overlooked at one point. The mixture was made correctly, but I'll need more to attain the number I desired:

2 tsp of this liquid magnesium solution will raise 1-gallon of aquarium water 25ppm. For me to raise the level in my reef 100ppm, it would take four times as much liquid, or 8 tsp per gallon. I'd need 3600 teaspoons for the 450g liquid volume of my reef. That's too much counting, so I checked and it would take 4.7-gallons of the magnesium solution to raise it up 100ppm.

At least now I know I'm definitely not overdosing it.