Lowering Mg

Date..........dKH....Ca..pH..sg.....Mg
2009-01-05 13 dKH 380 8.4 1.026 1340
2008-12-29 12 dKH 360 8.4 1.025 1420
2008-12-23 11 dKH 400 8.4 1.026 1420
2008-12-15 11 dKH 380 8.4 1.026 1380


OK, what I'm looking at here is I did a water change on 12-16 and got my numbers as shown for 12-23.

I've been measuring Mg for about 9 or 10 weeks. Over about 4 weeks it climbed from 1320 to 1480 and held for two weeks. In a different thread it was theorized that had more to do with me getting more accurate at testing it. I believe that.

So my Mg experience is as such. Then, a week ago, I added my first corals. Xenia, Colt, Anthelia, and GSP (yay me!). And about two weeks ago I added a skimmer.

Tested my water today and my dKH and Mg readings were a bit surprising. I retested both to be sure. My dKH is suddenly 13 and my Mg is suddenly dropped a good chunk to 1340. I have another water change scheduled in three weeks. (I do them every six).

So my question is: do you think this sudden change in dKH and Mg (which I've never seen before) is related to the coral addition? The skimmer addition? Both?

I've tested dKH since the beginning. I've only seen increases after WC's. I've only tested Mg for about 10 weeks, so I may have simply not noticed it before and this is its natural cycle. I will continue to monitor over next several weeks of course, but wanted your take on it.

I've read the relationships of Alk, Ca, Mg article and it seems these numbers are moving together as they should... it's just different from what's been normal to me.

(The second CA rise is because I dosed Red Sea 3+. I won't be using this product anymore as it doses iodine and I don't test for that)

Any recommendations or just do my WC in three weeks as planned and keep testing?

 

I wouldn't worry about it at all. I'd toss another shot-glass or two of epsom salt mixed in with a few cups of RODI water and add it in for good measure. Even 1500 ppm is fine, you just don't want it too low, that's all.

 

I'd get the Ca to 420, the pH to 8.3, DKh 11, and keep the Mg high 1400's....but that's just me ;D

 

what type of salt are you using?? not only do most salts lack in almost every element they will also very from batch to batch. Before i took my tank down i switch to D-D's new H2Ocean MG pro plus with FANTASTIC results... and then of course the hydroids starting spreading like wildfire...

 

I use Instant Ocean. There was a thread a while back that had a study of the elements in various salts. Instant Ocean scored well in this aspect. Not the best, but well.

I do plan on raising it now with Epsom's. Going to mix probably 2 shots in 3 gallon top-off - have it in over a three day period.

 

yes IO is, i think, one of the most used because of its consistency and the buyer knows what they are getting almost every time.

 

A simple Google of bad batches of Instant Ocean would tell you how wrong this statement is. There are always polls on which is the best salt. I usually stay out of them. The truth is, there are issues with every brand of salt.....pick your poison. One might have too much Borate usually, one might be too high on Magnesium usually, one might be too low on Calcium usually, etc. PICK YOUR POISON! That is why you test your waterchange water for important parameters BEFORE you do the waterchange.

Just so everyone knows....IO is intended for FO or FOWLR tanks. Their product called Reef Crystals is intended for reef tanks. IO is often used simply because it's cheapest and then others supplement what is missing on their own.

 

Currently my Mg is around 1640. A little high for my tastes but OK if the Ca and dKh are up there to match. Normally, I shoot for a dKh of 12 to 15, a Ca of 460 and a Mg of 1550. Now as I have obviously overshot my 1550 mark, I am going to bring my Ca up to about 500 to balance it out a bit. Try to keep a Ca:Mg of around 1:3.25. A higher dKh on top of it will stabilize things out.

 

Lets not forget the lithium, copper, cadmium and lead issues! Just the stuff I WANT in my salt. Even after reformulation, IO has raised the big three abit(Ca, Mg and Alk) but not that high. RC isn't ALL that much better for the elevated price. Red Sea is a comperable price to RC plus you get a 200 gal bucket instead of 160 and it has a little bit better makeup of the big three.
Like inwall stated, EVERY salt has issues, some just have more than others!

Happy reefing!
Or and peredihill, I would use MgCl2 if you are using it long term....

 

For the mix of inverts you have, to me it seems like you keep the levels awfully high. Do you have a reason for this?