An imaginary penny for your thoughts

[AquariumMasterIsenberg]

What would you do?  My tank seems pretty stable regarding pH, alk, Ca, and Mg.  My results are generally:
pH-8.0
alk-3.5meq/9.8dkh
Ca-375
Mg-1200
My routines are 10gallons of water changes a week in a 46gallon w/ 15-20gallon sump.  I add 2 capfuls of C balance everyday.  Usually every other week I dose SeaChem alkilinity builder stuff that says it safely raises pH to 8.3.  After I dose the pH and alk will go up a little and slowly work back down to the above.  I'm just curious what people think.  I've really been trying to get my Ca up to 400, but it doesn't want to move.

[michael]

you wont ever get your calcium to stabilise because your magnesium level is very low, 1350-1400 imo is a good level, you should get your calcium to 420-440 and it should stabilise a little when the mag is right, of course you need to monitor params to keep the levels right and dosing with most reef tanks is needed either by 2 part or kalk, as for mag well mag flake is useful, of course a decent salt helps.

the correct levels are slightly lower than those i mentioned but as we dont get refreshing new salt water into the tank unless we water change a bit of a margin is required, so sort out the magnesium level and the calcium should stabilise

[AquariumMasterIsenberg]

My water comes from the Pacific Ocean via the Seattle Public Aquarium, so I don't mix my salt.  I figured it would be hard to beat water from the ocean.  C Balance is a 2 part supplement.  I have magnesium which I have not yet used, but could definitely start adding some.  I will do that tomorrow.  Thanks Michael.

[michael]

fair enough, but the levels are still low, you need to up the magnesium, its being used up somehow, and even if the water is from the ocean, you wont get stable calcium if the mag is low

[Bonneville08]

I agree with Michael about the Magnesium level being too low. I've read that alkalinity and pH should also stabilize when Magnesium is correct.
Russ

[H2-0WE]

somebody else was using Seattle's finest on RC? My 2 cents? umm the water you are using is something they are discarding, that should speak volumes to you. all your really getting is water full of bacteria and life thats not suitable in a quite warm by comparison tank, everything in it will just be adding to your detritus load

[H2-0WE]

just a thought, 4 cents now lol. as the additives your using are meant for synthetic salt mix Im wondering just how effective they are on real salt water? there is quite a big difference between the two

[Jimw369]

Yup....what Micheal and Bonn said.  Raise that mag to 14-1500 and keep adding that 2 part till you reach the level you want.  If your alk is fine then just dose the Ca.  People make all this sound like rocket science and it aint!  Pour some Ca in there wait and hour and test...do it again and again till its up there and then monitor your usage every day so you know what amount to keep dosing.  I can say Ive moved tanks 4-5 times over 150 ppm over the course of a day with the Ca with no ill effects.  Just raise the mag over a few days and then when that tests fine start dosing the Ca.

[AquariumMasterIsenberg]

somebody else was using Seattle's finest on RC? My 2 cents? umm the water you are using is something they are discarding, that should speak volumes to you. all your really getting is water full of bacteria and life thats not suitable in a quite warm by comparison tank, everything in it will just be adding to your detritus load

That's an interesting thought.  I could recheck into it.  When I originally did, my understanding was that they offer to sell water to local fish stores that they put into their tanks, not after its been in their tanks.  My understanding was it is collected from the ocean, run through a variety of filters and sterilizers, and then they sell it.  They have all the fancy equipment, why not?  My LFS uses it for all their stuff and I'd have to say the evidence would say that it is working for their's and the aquariums they service.  I don't think I'm having problems with the additives not working.  I've been able to make positive changes using these products in my current set-up and previously when I used different water.

[AquariumMasterIsenberg]

The magnesium level is what stumps me a little bit.  My magnesium bottle says that 1200-1350 is the target range for magnesium and it seems to me that I've read in a few places that natural sea water is around 1250 or so.  I do have a bunch of pom pom xenia and a few mushrooms, if they do indeed use up magnesium.  However, my magnesium level has stayed pretty constantly at 1200 the last 4 months I've been testing it, so I wouldn't think the corals would be eating up magnesium.

[michael]

h--mmm, well if the system is working and your getting growth then thats great, but you wont be able to raise calcium unless your mag is 1350 ish or a little higher, at 1200 the levels are low and calcium wont stabilise, not 100% sure what the mag levels are in the ocean, but i always though 1350, something for me now to research i suppose

[Flipside]

Have you tried changing out one gallon of water a day?  I started and my tank is looking NOICE! 

[Bonneville08]

According to Bob Goemans, in one of his excellent books, the concentration of Magnesium in NSW is 1280, and Calcium is 400 at 35 ppt salinity. I do not disagree with raising the level for the sake of stability, among the many functions of Magnesium, it is a major portion of alkalinity in NSW. I try to shoot for 1400 ppm myself.

[Teric]

BAM! He just broke out the bible.
In all seriousness now, if magnesium is directly related to calcium, having high levels of calcium means I also have high magnesium levels? I was wondering because I don't have a magnesium test kit yet but I do have calcium and the other day when I checked it, it was about 520.

[Bonneville08]

I think that it might be more complicated than that Eric. I think you need a reasonable amount of Magnesium to maintain Calcium level, but I would prefer to measure it quantitatively.