water chemistry (long post)

[amee6730]

I have only started testing/dosing magnesium for about 2 weeks. I use IO salt. The first magnesium test I did was 1080. (NSW=1300-1500 depending on salinity) So I dosed B-Ionic magnesium supplement as directed on the bottle and re-tested in 3 days. The magnesium was up to 1170 but KH (alkalinity) was down to 9.9 from 11.0 before I started dosing and calcium was down to 300 from 400 before I started dosing magnesium. I've always used Kent turbo calcium but switched to B-Ionic 2 part buffer/calcium supplements at the same time (2 weeks ago). I have been adding equal parts like it says.

Tonight (2 weeks from starting to dose magnesium and changing to B-Ionic) my water tests are this: salifert test kits

Temp 82
sg 1.025 (with refractometer)
pH 8.3
nitrate 5
nitrite 0
KH 8.0 !!!
Calcium 370
Magnesium 1230

Tonight I dosed B-Ionic part A (buffer) and the KH re-tested 10.5, then dosed kent's Turbo Calcium until calcium tested 430. Then tested KH again and it had already dropped to 8.2 again. What's the deal? Should I have left well enough alone and never started dosing magnesium? The alkalinity was fine then. I only started because I thought raising magnesium would also help raise calcium (which I could never get above 400 before). If it's gonna mess with the alkalinity that much, should I just stop and live with a calcium of 400 or will all of this straighten out with time?

All corals still look fine. I even re-read the directions on all the bottles and on the test kits to make sure I did everything right.

[Woodstock]

Hummm... are you seeing any calcium precipitation after dosing? Any type of 'fog' or dust like sediment on the sides, pumps, etc? Maybe you're overdosing and it's precipitating? Does the B-Ionic mg supplement have ca/alk in it also?

[amee6730]

I was thinking the same thing (precip), but I was thinking along the lines of suddenly the whole tank being extremely cloudy. But now that you mention it, there is this fine dust on the glass. I scrape it off and it's right back on in 30 minutes. I bet that's it! I was thinking it was fine particles of sand. There is a thick, thick, beige coating in the skimmer cup that is new too. Very tough to get out. I'm going to stop trying to get the "perfect" numbers and leave well enough be. The numbers were decent and corals were fine before I started messing with everything! Or maybe ponder the idea of changing salt.

(karma 2 u...thanks)

[Woodstock]

You're welcome Amee Keep us posted~

[Boomer]

Stop using Kent turbo, it is not a balanced sup and is why you are having problems, the tank is in an ionic imbalance. Kent turbo should only be used to sup Ca when all other parameters are Ok, i.e., pH, Alk and the Ca is low. It is a one shot deal. Once the Ca is up to normal STOP using turbo and go back to two-part sups. You will need to do some water changes now as the problem will just persist if you don't

[reefrelief]

Why not consider using a product such as the C-BAlance by two little fishes. You could never overdose anything so long as you give the prescribed dosages and it gives the recomended dosages for all trace elements as opposed to trying to balance several different products by several different manufactures. Also if you are having problems raising your calcium you should do one of a few things, the first being more frequent water changes and the second using a product such as Kent's Liquid Reactor which I had found to cure all of the calcium/alkalinity woes. A good thing to know also is that your magnesium will never be where it is supposed to be if the calcium is not. Having said that, if you wish to correct your magnesium anamloies you have to first correct your calcium anamoly. Calcium supports magnesium, nothing else.

[amee6730]

Thanks for the tips guys. I'm going to stop dosing mg for now and do some water changes. Then just concentrate on keeping the calcium and alkalinity in check by using the 2 part b-ionic and leaving the turbo ca alone. I had no idea about the turbo ca ionic deal. It was recommended to me about 3 years ago by the LFS and I never questioned it. :smck:

Does this sound OK?

[cheeks69]

RHF:

Magnesium is an important ion for reef aquarists. In addition to its many biological functions, it serves to prevent the excessive precipitation of calcium carbonate from both seawater and aquarium water. Since both calcium and alkalinity are very important to organisms that we keep, making sure that they are not lost to excessive precipitation is an important part of aquarium husbandry.

http://www.advancedaquarist.com/issues/oct2003/chem.htm

Magnesium's primary importance is its interaction with the calcium and alkalinity balance in reef aquaria. 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 growing surface of the calcium carbonate crystals. 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, so the precipitation stops. Without the magnesium, the abiotic (nonbiological) precipitation of calcium carbonate would likely increase enough to prohibit the maintenance of calcium and alkalinity at natural levels.

http://www.reefkeeping.com/issues/2004-05/rhf/index.php

[cheeks69]

Amee I used to dose a 2 part cal/alk supplement and later on had some serious problems. Most salt mixes are imbalanced to begin with so you have to measure regularly before adding the 2 part don't just dose the same amount everyday check what your tanks cal/alk needs are then dose appropriately. What I have done is drip kalk every night and add cal or alk as needed and my tank has never been better.

[amee6730]

I tested my water change water tonight to make sure I didn't get a bad batch of salt and got this:
temp: 80
SG 1.025
pH: 8.4
alk: 9.3dKH (3.31meq/L)
Ca: 330
Mg: 1200

OK, it wasn't the salt. So I added B-Ionic A&B and magnesium, re-tested and got this:
alk: 10.3dKH (3.67meq/L)
Ca: 410
Mg: 1290

Then I did a 10% water change. I plan to do another 10% change every 2-3 days until everything stays stable. I tested the tank after the water change and got this:
alk: 9.9dKH (3.54meq/L)
Ca: 430 (I don't know how that happened)
Mg: 1230

So now I'm happy. I'm going to test often and do frequent water changes. After reading and re-reading the links Robert posted, I concluded it was not dosing the magnesium that caused everything to get out of whack. (thanks a million, Robert ) Could it have been me raising the alkalinity too fast? Whatever the cause, I'm not going to over react to a number anymore and make any adjustments very slowly. I guess even a bad number is better than a rapid change of any kind...lesson learned. I'm just thankful that the tank has looked great through everything!

[Boomer]

Amee

Then I did a 10% water change. I plan to do another 10% change every 2-3 days until everything stays stable. I tested the tank after the water change and got this:
alk: 9.9dKH (3.54meq/L)
Ca: 430 (I don't know how that happened)
Mg: 1230

Yes, this pretty proves my point.

Could it have been me raising the alkalinity too fast?

Yes, it may have been, as adding alk by itself is often a means we use to lower the Ca if it is to high but turbo is CaCl and it is the Cl that throws the tank out of wack usually. This type of addition of CaCl causes an imbalance in the ratios of ions in the water that makes the ions adjust to a different balance, set of parameters. This type of solution is always trying to go back to where it was, kinda like those you were getting. Trying to make adjustments with sup's does not seem to help and the water just goes back to where it was. Water changes will bring things back in line. When one uses something like turbo it is only when the Ca is low and the Alk is Ok, i.e. Ca 380, Alk 3.5 meq/ l, add turbo until Ca get so say 410, stop the addition of turbo and go back to two-part.

There are a number of ways to keep the tank in balance with sups based on the tanks needs. What ever the case may be they always need to be balanced additives, when used on a day-day sup. There are 3 types of balanced sup's; Kalk, two-part and calcium reactor. For most of use, if we can do it, kalk is by far the best sup. Two-parts are really not perfect sup's like kalk and in time can throw the tank into an imbalance. The issue of Ca-reactors is all the other stuff in the media that ends up in the tank you may not want. Many use two of these sup's together which is fine. We also have calculators to help ones needs, see links below.


How to Select a Calcium and Alkalinity Supplementation Scheme
http://www.advancedaquarist.com/issues/feb2003/chem.htm

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

When Do Calcium and Alkalinity Demand Not Exactly Balance?
http://reefkeeping.com/issues/2004-12/rhf/index.htm

Reef chemicals calculator
http://home.comcast.net/~jdieck1/chem_calc3.html

ChemPlot
http://www.reefnerds.com/ChemPlot/ChemPlot.html

[amee6730]

Thanks again. I especially liked the article "When Do Calcium and Alkalinity Demand Not Exactly Balance?" and the calculator. I read the others yesterday. All great helps. I really had no understanding of how alk, ca, and mg interacted with each other, only that they did. All I knew were the "normal" values and when they were not "normal" I "corrected" them with chemicals. The whole time I was creating an unstable or unbalanced environment.
I have a new respect for the younger reefers now. I struggled with some of the terminology and even had to look up some stuff in my old college text books (and I have a medical background). I must admit, I looked like a mad scientist last night at the kitchen table! I don't know how jr. high and HS students do it!

[Cisco Kid]

Outstanding articles Boomer. Helped me before I could ask the questions.