Let's talk about Alkalinity, Calcium and Magnesium in an SPS Tank

[Lyfey]

In my 75gal DT/ 30 gal sump, roughly 89 gallons total water volume. I used 1 cup of epsom salts disolved in 3-4 cups RO/DI and it raised my MG from 1250 to 1300. Using these calculators are difficult because they dont support brightwell suppliments and who knows how many grams of epsom salts? I dont have a scale for that. They should have a more "user friendly" calculator with common measurements. Just my expirience for raising MG.

 

[melev]

Your method isn't a balanced one, if you are trying to match water chemistry. You need Magnesium chloride to go with the Magnesium sulfate you have. Just taking a cup of Epsoms Salt alone is unbalanced, and we know it is all about the ions. Following RHF's Recipe #2, I use 7.25 cups of Mag Flake and .75 of a cup of Epsoms Salt carefully mixed with 1 gallon of RO/DI water.

I use Jose's calculator. If he needs to add Brightwell's additives to it, ask him.

 

[Lyfey]

What exactly does the "balance" issue unbalance? I understand doing it this way is unbalanced, but all I had was the epsom salts. When a system is "unbalanced" what happens?

 

[melev]

I'd have to refer you to Randy's Magnesium article to provide the facts. Off the top of my head, Epsoms Salt will definitely affect salinity when a lot of it is used.

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

 

[Laddy]

I disagree with respect to raising Mg levels in one big addition.

I've always tried to keep my levels north of 1300, with an average around 1350, by mixing up mag chloride with my RO/DI water and letting the mixture get added when the top-off kicks on. It's dump and forget, to a certain extent, and it really prohibits large swings--depending on evap and pump strength.

 

[Aquarist007]

Since IO has come out with new higher levels of magnesium in its salt mix I have not had too much of an issue with mag levels.

 

[Aquarist007]

I'd have to refer you to Randy's Magnesium article to provide the facts. Off the top of my head, Epsoms Salt will definitely affect salinity when a lot of it is used.

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

apology for the off topic question here

Marc, a local guy here wants a 300 gal tank but split so half can be a predators tank and the other a mixed reef. He says he got the idea from the States. Do you know of such a setup?

 

[dvanacker]

I'd have to refer you to Randy's Magnesium article to provide the facts. Off the top of my head, Epsoms Salt will definitely affect salinity when a lot of it is used.

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

The issue with using only magnesium sulphate is the increase in sulphate concentations.

 

[mranthonymb]

def good stuff to know and im not goin to lie i only read to page 5 so far but i have a question
i have a 90gal tank up for about 4 or 5 months with only a dendro and like 3 zoa frags..... my question is should i start playing with the Alk Mag and Cal now before i start with the SPS or after???
i am planning on doing it soon but wonder what yall think

 

[ssublime1]

Measure and practice keeping your parameters in check for a while before adding sps. If you have the time, I would check these daily for a couple weeks to see if and how much they change day to day.

 

[tyreeftank]

I have a hard time maintain my calcium to 400. I am use a Kalk reactor for dosing calcium and alk. Is there anything else that I can do.

 

[Aquarist007]

I have a hard time maintain my calcium to 400. I am use a Kalk reactor for dosing calcium and alk. Is there anything else that I can do.

how big is you tank and is it predominately sps corals?

 

[tyreeftank]

75gal tank with couple sps corals.

 

[melev]

You may need to buffer up the calcium with a commercial product, tyreeftank. Then the kalkwasser can maintain it.

 

[tyreeftank]

Thank for the info. I will to buffer up with calcium.

 

[Aquarist007]

Thank for the info. I will to buffer up with calcium.

suggest a chloride so it has minimum impact on the alk levels

I like using Kent Turbo Calcium

dosing can be expensive so I suggest you use one of the better quality salt mixes available on a regular basis. I like using Reef Crystals--its numbers are higher then others.

here is a list of what is in the major brands of salt mixes

http://reefcentral.com/forums/showthread.php?t=1287118

 

[Aquarist007]

You may need to buffer up the calcium with a commercial product, tyreeftank. Then the kalkwasser can maintain it.

Marc---what is your preferred level for ca, alk and mag for a predominately sps tank.

 

[melev]

Pretty much what Randy has recommended, to match NSW (Natural Sea Water) parameters.

1.026sg
8-11 dKH Alkalinity
375 - 450ppm Calcium
1300 - 1350 ppm Magnesium (I try to keep this one at 1400)

 

[mranthonymb]

Measure and practice keeping your parameters in check for a while before adding sps. If you have the time, I would check these daily for a couple weeks to see if and how much they change day to day.

thanks i will do that forsure

 

[tonyf]

suggest a chloride so it has minimum impact on the alk levels ... dosing can be expensive so I suggest you use one of the better quality salt mixes available on a regular basis. I like using Reef Crystals--its numbers are higher then others.

Calcium chloride from your local pool shop is a cheap and effective substitute over expensive 'marine aquarium specific' products.

Tone :thumbsup: