Let's discuss...salt.
You'd think that salt mixes emulating the ocean would all be real similar...and you'd wonder why some cost more than others. Prettier package? Crazy pricing?
Well, not so much that...as salt for various purposes. PURE salt is sodium chloride, NaCl...but that won't do. [Yes, somebody always asks, can I use Morton's table salt?---no. That would be a disaster.]
If you look at the label of your salt mix, you'll see a very, very long list of what's in there besides sodium chloride.
And if you compare the labels of two or three salt mixes, you will turn up some significant differences.
Two main ones are fish-only salt; and reef salt. They differ from each other in (principally) how much calcium they contain. Fish-onlies don't consume as much calcium as reefs, where one little hammer coral or clam can suck down an amazing amount of calcium, thus throwing the water balance 'off' pretty quickly.
Fish-only salt is cheaper, because it contains a little less than the reef salt. Now, could you dose calcium, magnesium, and buffer and get up to reef levels? Yes, but you'd spend money doing it...which is that price difference.
Reef salt has that extra stuff that corals need...and if you have softies, your water changes at 10% a week, even 20% a month---will supply the laundry list of trace elements a softie reef needs.
Stony corals, however, are hungry for calcium, because that's how they form that stony skeleton, and you will have to supply that extra calcium for them by dosing. This, fortunately, is as simple as tossing lime powder into your ATO reservoir: but---as you might expect---just a wee bit more complicated: you'll want the alkalinity (capacity of the water to handle acidity) to help it dissolve---a good level for alkalinity is 8.3 [range is 7.9-9.0] and it needs magnesium, which gets used far, far, far more slowly, at a 'good' range of 1300-1350. And you'll want to hold your calcium at 420. Lime in your ATO will deliver that beautifully if you have enough magnesium in your water and if your water is buffered to a nice (8.3) level. You don't even have to measure the lime dose that precisely. Ocean water can only dissolve enough calcium to make it all work nicely, when conditions are 1350 mg and 8.3 alk. You can't overdose. How do you dose? There's two-part; there's the separate elements as dkh buffer, calcium, and magnesium. You dose those to get your water in perfect balance, then toss lime powder (I use Mrs Wages' Pickling Lime, no kidding) into your ATO and kick back and relax for a while, because that balance will hold solid as a rock until the magnesium gets used down to 1200.
Now we get to the part where 'no reef salts are equal, either.' And they aren't. Some reef salts are better for really packed reefs...Oceanic brand delivers a LOT of magnesium, useful if you have wall-to-wall big coral sucking down minerals by the spoonful. Instant Ocean delivers less magnesium, which may be much better for a tank just starting its growth, so that magnesium will not stack up and up and up unused. Yes, you can change brands, but do so in knowledge, not by 'what's on sale.'
There's one more caution. Buying salt in barrels is significantly cheaper, but settling may occur, and just occasionally there is a 'bad batch' of salt. Shaking up or rolling a partial barrel may help mix it up. It's a good practice. Secondly, if you are getting weirdness in your tank---ask yourself when you started using a new barrel. Ask yourself---is this the best salt for this stage of my tank? The answer can change over time. And brands can change, for what reasons I don't know---possibly the source of the salt they're buying.
People ask: should I dose [fill in blank: selenium, iodine, etc, etc, etc.] The general answer is a resounding no. Not until you're an expert in coral culture with a particular coral with a particular need, which is not for a number of years yet. Your water changes will solve that problem, supplying all those lovely trace elements that your corals need, in the proportions they need them, in the amounts they need. Don't mess with the mix! Is it apparent now why we say zero TDS (total dissolved solids) ro/di is the best water to use for a mixing base?
You may, however, question which mix is best for your situation, and which mix will not let one of the Big Three (alkalinity buffer/calcium/magnesium) build up to excessive levels in your particular situation. It does require some thinking and label-reading, and asking around.
__________________
You'd think that salt mixes emulating the ocean would all be real similar...and you'd wonder why some cost more than others. Prettier package? Crazy pricing?
Well, not so much that...as salt for various purposes. PURE salt is sodium chloride, NaCl...but that won't do. [Yes, somebody always asks, can I use Morton's table salt?---no. That would be a disaster.]
If you look at the label of your salt mix, you'll see a very, very long list of what's in there besides sodium chloride.
And if you compare the labels of two or three salt mixes, you will turn up some significant differences.
Two main ones are fish-only salt; and reef salt. They differ from each other in (principally) how much calcium they contain. Fish-onlies don't consume as much calcium as reefs, where one little hammer coral or clam can suck down an amazing amount of calcium, thus throwing the water balance 'off' pretty quickly.
Fish-only salt is cheaper, because it contains a little less than the reef salt. Now, could you dose calcium, magnesium, and buffer and get up to reef levels? Yes, but you'd spend money doing it...which is that price difference.
Reef salt has that extra stuff that corals need...and if you have softies, your water changes at 10% a week, even 20% a month---will supply the laundry list of trace elements a softie reef needs.
Stony corals, however, are hungry for calcium, because that's how they form that stony skeleton, and you will have to supply that extra calcium for them by dosing. This, fortunately, is as simple as tossing lime powder into your ATO reservoir: but---as you might expect---just a wee bit more complicated: you'll want the alkalinity (capacity of the water to handle acidity) to help it dissolve---a good level for alkalinity is 8.3 [range is 7.9-9.0] and it needs magnesium, which gets used far, far, far more slowly, at a 'good' range of 1300-1350. And you'll want to hold your calcium at 420. Lime in your ATO will deliver that beautifully if you have enough magnesium in your water and if your water is buffered to a nice (8.3) level. You don't even have to measure the lime dose that precisely. Ocean water can only dissolve enough calcium to make it all work nicely, when conditions are 1350 mg and 8.3 alk. You can't overdose. How do you dose? There's two-part; there's the separate elements as dkh buffer, calcium, and magnesium. You dose those to get your water in perfect balance, then toss lime powder (I use Mrs Wages' Pickling Lime, no kidding) into your ATO and kick back and relax for a while, because that balance will hold solid as a rock until the magnesium gets used down to 1200.
Now we get to the part where 'no reef salts are equal, either.' And they aren't. Some reef salts are better for really packed reefs...Oceanic brand delivers a LOT of magnesium, useful if you have wall-to-wall big coral sucking down minerals by the spoonful. Instant Ocean delivers less magnesium, which may be much better for a tank just starting its growth, so that magnesium will not stack up and up and up unused. Yes, you can change brands, but do so in knowledge, not by 'what's on sale.'
There's one more caution. Buying salt in barrels is significantly cheaper, but settling may occur, and just occasionally there is a 'bad batch' of salt. Shaking up or rolling a partial barrel may help mix it up. It's a good practice. Secondly, if you are getting weirdness in your tank---ask yourself when you started using a new barrel. Ask yourself---is this the best salt for this stage of my tank? The answer can change over time. And brands can change, for what reasons I don't know---possibly the source of the salt they're buying.
People ask: should I dose [fill in blank: selenium, iodine, etc, etc, etc.] The general answer is a resounding no. Not until you're an expert in coral culture with a particular coral with a particular need, which is not for a number of years yet. Your water changes will solve that problem, supplying all those lovely trace elements that your corals need, in the proportions they need them, in the amounts they need. Don't mess with the mix! Is it apparent now why we say zero TDS (total dissolved solids) ro/di is the best water to use for a mixing base?
You may, however, question which mix is best for your situation, and which mix will not let one of the Big Three (alkalinity buffer/calcium/magnesium) build up to excessive levels in your particular situation. It does require some thinking and label-reading, and asking around.
__________________
