Few questions About Calcium/Mag

Discussion in 'Water Chemistry' started by destinationluna, Mar 18, 2011.

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  1. trijam

    trijam Coral Banded Shrimp

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    Everytime you do a water change it will dilute down your concentrations of mg and ca. You want this to be a gradual drop otherwise inhabitants may suffer. If you are doing 20% WC/month it will probably take about three mos before your concentrations come down to proper range unless you add something like a clam that would use the ca and mg much faster than the corals you currently have. I use IO Reef Crystals and my ca is always 440 and mg 1350.;)
     
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  3. Corailline

    Corailline Super Moderator Staff Member

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    It is a dry heat, yeah right !
    I have been using IO since 1996, and have never had an issue with parameters other than simply adjusting the magnesium level as needed.
     
  4. destinationluna

    destinationluna Skunk Shrimp

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    Lol was just looking and was just gonna ask what do you think about reef crystals. as for my water changed I do 10-15% a week to keep my nitrates at 0 my TWV is 129Gallons I change 10-15 Gallons a week. If not I seem to have issues with alk and ph and the sort. I dont really have to dose due to the fact that there is not much coraline in there as of yet and most of my frags are small and are soft corals so they dont take any out of my system.

    The main reason I want these levels at what they should be is I do plan on adding hard corals so Just want to get things right before I do that. I currently have one Acro in there and it seems to be doing ok. But its new so will see how it goes. I have not noticed any growth on it yet but like I said its new. I have a duncan that just loves it in there he is growing like a weed and some zoa's that i picked up about a month ago they are doing great too. so hopefully getting the right salt mix will just improve there lives in there while giving me piece of mind that everything is going well
     
  5. Peredhil

    Peredhil Giant Squid

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    It'll eventually come down on its own. IME Mg doesn't drop all that fast though so it would take some time.

    As far as WC, this reduces it only if the WC water has a lower Mg reading than the system.

    IO tends to have a Mg reading of around 1100. (So, usually, I dose my WC water before using it to bring Mg up to around 14-1500). So if you don't dose the WC water you'll be taking out X gallons of 1600 Mg and replacing it with X gallons of 1100.

    It's a 500 point difference but only on Y percent of your water (the amount you're changing). For reference, I have found that in my 55, doing a 5 gallon WC without dosing will take my Mg from 1700 to 1620 (Yeah, I had a Mg overdose accident a while back).

    Limit your drops to no more than 100 points.
     
  6. banthonyb71

    banthonyb71 Millepora

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    One thing you did not mention is your salinty. As if this is to high it will definatly make you read high mag levels. What is your specific gravity? What type of device are you using to test it? If hydrometer, what kind? I would strongly reccommend either a refractometer or 2 hydrometers as somtimes hydrometers are inaccurate. I was told thid as a newb by somone on here and Im glad I listened to them as I found I had waay to high salt gravity from faulty hydrometer.

    Instant Ocean is genrally for fowlr tanks. IO Reef Crystals is for mixed reef tanks. You will probably need to dose somthing with either 1 you use, however if you really want lower levels and want to manually dose more often, then use Instant Ocean BUT IO willl not have all the essential trace elements as R C.

    I agree with a couple other statements. Reef crystals usually keeps my cal in the low 400's.

    another statement I agree with is the person who said your cal should not be that high if your not dosing. Somthing up with your test kits or salinity. imo.
     
    Last edited: Mar 18, 2011
  7. destinationluna

    destinationluna Skunk Shrimp

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    2 hydrometers read 1.026 i think its a salt issue coralife salt says 450ppm calcium but thats at there mix rate of 1.021 - 1.023. Think im gonna switch to RC cuz its like you said designed for 1.026 so calcium/mag in there is added to compensate for high or normal ocean salinity. Waiting for the good old tax return to come in im ordering a refractometer from marine depot. Along with about $300 more goodies haha.
     
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  9. Peredhil

    Peredhil Giant Squid

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    IO is perfectly fine for reefs. I don't know why anyone would say they don't have all the trace elements needed. Plenty of people use it exclusively for reef tanks. I'm not saying IO is the best, but I am saying it's the only salt mix my mixed reef has ever used...


    Mg is a salt. Raising your Mg level will raise your SG level - having high SG levels will show you have high Mg levels, if your Mg levels are high. There are many ways to raise SG - Mg is one of them.

    I do agree if your Mg is that high your SG level is also going to be elevated. But the reason SG is high is bc Mg is high - not the other way around if you're reading Mg at 1600+ currently.

    Hydrometers are trash, refractometers are reliable; agreed.

    Your Ca reading, like I said earlier, is currently an unknown. With Mg levels that high it impacts Ca tests. This has been shown to be true, at least, with both API and Salifert test kits. I suspect it is true for the others as well.

    While I agree your Ca will only get that high through dosing, I do not agree we know what your Ca level actually is.
     
  10. destinationluna

    destinationluna Skunk Shrimp

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    Alright so just for ****s and giggles went and picked up another hydrometer until i get my refractometer in. Check it and bam 1.028 there is the problem. Got some work to do i guess to bring that down some.
     
  11. Peredhil

    Peredhil Giant Squid

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    yes. that is what happens when your Mg is that high. It raises your SG.

    That is a different 1.028 than you would have if you were, say topping off with SW. Does that make sense to you?

    Because of that, it's not the SG reading that is the problem, per se but the inflated Mg reading that is the problem.

    You want to focus on bringing the Mg down, not the SG to keep your balances correct. You'll end up bringing down the SG as an effect of lowering the Mg.

    EDIT: also, I wouldn't trust the new hydrometer either ;)
     
  12. Peredhil

    Peredhil Giant Squid

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    unless, were you topping off with SW?

    It only now occurred to me that I have been assuming you have overdosed Mg and/or Ca specifically...

    Would you mind clarifying that for me?