Here is the current ReefKeeping Mag article by Randy-Holmes Farley that sums up what supplements that he feels are neccessary and those that he feels are not. I do know that the magority of speakers (Calfo, Borneman, to name a few) do not recomend adding any supplement to an aquarium other than calcium. So read and decide for yourself. http://www.reefkeeping.com/issues/2007-04/rhf/index.php
From Text "Alkalinity Target Levels Like calcium, many corals also use "alkalinity" to form their skeletons, which are composed primarily of calcium carbonate. It is generally believed that corals take up bicarbonate, convert it into carbonate, and then use that carbonate to form calcium carbonate skeletons. To ensure that corals have an adequate supply of bicarbonate for calcification, aquarists could very well just measure bicarbonate directly. Perhaps some day that will be done. For now, alkalinity is a surrogate measure that is perfectly adequate because bicarbonate greatly dominates all other ions that are added together to measure total alkalinity. Unlike the calcium concentration, it is widely believed that certain organisms calcify more quickly at alkalinity levels higher than those in normal seawater. This result has also been demonstrated in the scientific literature, which says that the uptake of bicarbonate can apparently become rate-limiting in the growth of some corals. For these reasons, alkalinity maintenance is a critical aspect of coral reef aquarium husbandry. In the absence of supplementation, alkalinity will rapidly drop as corals use up much of what is present in seawater. Most reef aquarists try to maintain alkalinity levels at or slightly above those of normal seawater, although exactly what levels different aquarists target depends a bit on the goals of their aquaria. Those wanting the most rapid skeletal growth, for example, often push alkalinity to higher levels. I suggest that aquarists maintain alkalinity between about 2.5 and 4 meq/L (7-11 dKH, 125-200 ppm CaCO3 equivalents), although higher levels may be acceptable as long as they do not depress the calcium level. Supplementing Magnesium Magnesium is an important ion in reef aquaria. Like calcium and alkalinity, it can be depleted by various means if appropriate measures are not taken to maintain it. In order to prevent its depletion, or to correct a deficit when it occurs, magnesium supplements are often used. Magnesium's primary importance in reef aquaria is its interaction with the calcium and alkalinity balance. Seawater and reef aquarium water are always supersaturated with calcium carbonate. That is, the solution's calcium and carbonate levels exceed the amount that the water can hold at equilibrium. How can that be? Magnesium is a big part of the answer. Whenever calcium carbonate begins to precipitate, magnesium binds to the calcium carbonate crystals' growing surface. The magnesium effectively clogs the crystals' surface so that they no longer look like calcium carbonate, making them unable to attract more calcium and carbonate, stopping the precipitation. Without the magnesium, the abiotic (i.e., non-biological) precipitation of calcium carbonate would likely increase enough to prohibit the maintenance of calcium and alkalinity at natural levels. Supplementing Iron Iron limits the growth of phytoplankton in parts of the ocean, and may limit some macroalgal growth in many reef aquaria. Because of its short supply and critical importance, it is also subject to aggressive sequestration by bacteria and other marine organisms. Consequently, aquarists might consider dosing iron if they grow macroalgae. Iron is not easy to measure at levels normally encountered in marine aquaria. It also is not easy to determine which of its many forms are bioavailable in seawater, and which are not. Consequently, aquarists should not target a specific concentration, but rather should first decide whether they want to dose any at all, and then use an appropriate dosage going forward. The reason to dose iron is that macroalgae may benefit from it. If you are not growing macroalgae that are limited by iron, then you may not need to monitor or dose iron at all. Deciding how much iron to add is fairly easy because, in my experience, it doesn't seem to matter too much. Presumably, once you add enough to eliminate it as a limiting nutrient for macroalgal growth, extra iron does not cause apparent harm (at least none that I've detected in my aquarium or have heard of from others). The choices of iron supplements include Kent’s product, which is combined with manganese (which I do not prefer, but which might be useful); Seachem’s Flourish Iron (which is intended for freshwater planted tanks, but works fine for a reef aquarium); and various DIY recipes if you have access to chemicals. I’ve used all of these successfully. Just follow the label's dosing directions if you use a commercial product. Summary Reef aquarists add many supplements to their aquaria. Some are critical, some are beneficial for some reef systems, some may be a waste of time and money, and some may do more harm than good. Among the critical ones to use are calcium and alkalinity. Nearly every reef aquarist must supplement them in one way or another. Assuming that these two parameters start in an appropriate balance, they are most easily kept that way by using a system that adds a fixed ratio of calcium to alkalinity, with that ratio being the same ratio used in the formation of calcium carbonate, such as in coral skeletons. There is no single best system to use, but limewater (kalkwasser), calcium carbonate/carbon dioxide reactors, and two-part systems are the most popular, and each has its pros and cons that may make it a better fit for a given reef aquarium. Some aquarists combine two or more balanced additive systems (such as limewater and either a CaCO3/CO2 reactor or a two-part system), and that can be a good way to go, taking advantage of special attributes of the different system Magnesium supplements may be useful in some aquaria, especially those that use calcium supplements that do not otherwise add magnesium. Limewater, for example, adds little magnesium, while a two-part system may add all that is required. Many highly successful aquarists add nothing else. Those who grow macroalgae might usefully consider adding iron, and those growing sponges and certain other invertebrates might consider adding silicate. Folks who like to be on the more experimental end of things might consider adding certain amino acids and fatty acids, but I do not routinely add them. For my system, I add only limewater, iron and silicate. I boost the Instant Ocean salt mix that I use for water changes (1% of the water volume changed automatically each day) with calcium (70 ppm boost using Dowflake™ calcium chloride), as it is on the low side of normal calcium to start with. I also boost the Instant Ocean salt mix with magnesium (150 ppm boost using MAG Flake™ magnesium chloride) to offset magnesium losses in the aquarium. I do not, in general, recommend iodine, strontium, borate or trace element mixture dosing, at least for beginners. Whatever methods you choose to use for your aquarium, make sure you understand what you are adding and why. Then try to set a routine and stick with it. And don’t forget to enjoy your aquarium! Happy reefing! " (RHF) I'm Convinced !
I would love to read some articles about only dosing Ca. Or talk to someone who has been successful doing so. I tested my last batch of Reef crystals and it was: Ca 400 Alk 9.5 Mg 1250 @ 1.025 Which is ok I wish it was that @ 1.023 So if you did lots of changes you might not have to dose any thing else IMO I t is very wise to take caution when adding chemicals to a reef. depending on how heavily stocked your tank is; testing least once a week may be useful before you add ca and alk. Alk consumption seems to be heaver in some tanks as opposed to Ca. ??? Not sure where it goes? Mg might need to be checked up on every month. It also helps maintain Ca so if you have a hard time raising Ca. Try dosing Mg to stabilize it. Fyi S.V.U. Mg additive can be dosed every week depending on consumption. It is diluted for ????maybe safety reasons??? I don’t know. Dow Flake is stronger. Be careful. Fe needs to be dosed when growing Chaeto. When the Chaeto stops growing test for No3 and cut your dose. This will ensure that No3 stays at zero and Iron is not overdosed. For softy’s dosing may not be critical or necessary. Xenia (or how ever you spell it) starts looking wimpy when the Alk is to low. ??? Go figure. This is a quote from boomer in an interesting thread on C02 usage for macros
hear is the link for the hard core reef chemist. http://www.reefcentral.com/forums/showt ... id=1129385
Some alk is depleted by acids in the water, mostly Carbonic acid from dissolved CO2 at night. Oh, and Randy Holmes-Farley has presented data that doing water changes only on a tank to maintain Ca and Alk in an averagely stocked system would require ~30% water changes DAILY!!
yea dosing Ca only, the alk is depleated to a point where Ca can not be used. what is intresting is that the same can be said to be true for macroalgae and No3/Po4. hear is the link. http://www.reefcentral.com/forums/showt ... id=1141771
Randy says that Co2 or carbonic acid dose not effect TA (total alk), but other strong acids could. http://www.advancedaquarist.com/2002/2/chemistry yea I missed an LOL, but hay anything is possible in science…………………..jest not probable.
