newtosa
Wed, 19th Feb 2003, 03:30 PM
<< I threw this in a new thread; Chris can clean if necessary; otherwise at least we have an appropriately named thread. >>
DJDD -
As you're probably starting to realize, this can be a complicated topic.
Overview:
1. Ca test kits measure Ca++ ions in your water. Ca++ (as you probably already know) bonds easily with -- ("2-negative") elements or ions. This property is what drives most of calcium's interactions with carbonates and bicarbonates, as well as influencing how reef structure is built - whether in your tank or in the ocean. As a result, this property also drives much of the interaction between Ca, alkalinity, and pH.
Check out Ca here.... http://klbproductions.com/yogi/periodic/
2. pH is the measure of acidity: concentration of H+ ions in solution (more or less). Both biological (what's going on with the animals and plants in your tank all day and all night) and chemical (what the alkalinity is, what ions are being bound and released, etc.) processes are at play. Of the 3 parameters, pH usually (although not desirably) varies the most during a 24-hour cycle. You should shoot for somewhere in the high 7's (7.8 or so) just before lights-on to low 8's (8.3) just before lights-out.
3. Alkalinity in reef tanks means the resistance of the water to pH change. Since carbonates and bicarbonates are buffers in our tanks, it is typically determined by measuring CO3 and HCO3 ions in solution, and its units are commonly either mEq/L (2.5 - 3.5 is in our range) or dKH (degrees of carbonate hardness; 8-15 is in our range). There is a conversion factor for these, and I can't remember it right now.
General interaction:
As CaCl2 is added to a tank (Kent turbo calcium and most other Ca additives - even if it says calcium gluconate or "chelated" calcium), buffer ions are pulled out of solution, reducing alkalinity, and allowing pH to drop. Sustained additions like this will hurt you.
As a balanced Ca additive (KW, b-ionic, etc.) is added, you get free alkalinity boosts with Ca boosts, and free Ca boosts with alkalinity boosts (2 bicarbonate ions for every Ca ion, I think).
My Advice: do not attempt to control pH; rather, get alkalinity right and steady first. Then, as you're getting calcium up to where it should be, continue to monitor and maintain high alkalinity. pH will follow.
As complicated as this is chemically and biologically (it's way beyond my depth; trust me), it can be ridiculously simple in practice. Add KW drip, either at night or 24x7, as makeup water. If you're not keeping a lot of SPS corals, that's it.
I would recommend the following:
- Read http://www.aquariacentral.com/articles/calcium.shtml
- Read http://www.animalnetwork.com/fish2/aqfm/1998/june/bio/default.asp
- Read http://www.animalnetwork.com/fish2/aqfm/1998/july/bio/default.asp
- Read the Reefkeepers FAQ (at FINS or reefs.org) on this topic
- Search (maybe not post any questions) on RC for alkalinity and pH. Don't be afraid to lurk and read everything.
- Once you get a little more comfortable, do a search for the last name "Bingman." RC, google, wherever you can find. Read it all. I'll look in some printouts I have at home, grab the urls, and post a follow-up note.
Thanks,
Dean
DJDD -
As you're probably starting to realize, this can be a complicated topic.
Overview:
1. Ca test kits measure Ca++ ions in your water. Ca++ (as you probably already know) bonds easily with -- ("2-negative") elements or ions. This property is what drives most of calcium's interactions with carbonates and bicarbonates, as well as influencing how reef structure is built - whether in your tank or in the ocean. As a result, this property also drives much of the interaction between Ca, alkalinity, and pH.
Check out Ca here.... http://klbproductions.com/yogi/periodic/
2. pH is the measure of acidity: concentration of H+ ions in solution (more or less). Both biological (what's going on with the animals and plants in your tank all day and all night) and chemical (what the alkalinity is, what ions are being bound and released, etc.) processes are at play. Of the 3 parameters, pH usually (although not desirably) varies the most during a 24-hour cycle. You should shoot for somewhere in the high 7's (7.8 or so) just before lights-on to low 8's (8.3) just before lights-out.
3. Alkalinity in reef tanks means the resistance of the water to pH change. Since carbonates and bicarbonates are buffers in our tanks, it is typically determined by measuring CO3 and HCO3 ions in solution, and its units are commonly either mEq/L (2.5 - 3.5 is in our range) or dKH (degrees of carbonate hardness; 8-15 is in our range). There is a conversion factor for these, and I can't remember it right now.
General interaction:
As CaCl2 is added to a tank (Kent turbo calcium and most other Ca additives - even if it says calcium gluconate or "chelated" calcium), buffer ions are pulled out of solution, reducing alkalinity, and allowing pH to drop. Sustained additions like this will hurt you.
As a balanced Ca additive (KW, b-ionic, etc.) is added, you get free alkalinity boosts with Ca boosts, and free Ca boosts with alkalinity boosts (2 bicarbonate ions for every Ca ion, I think).
My Advice: do not attempt to control pH; rather, get alkalinity right and steady first. Then, as you're getting calcium up to where it should be, continue to monitor and maintain high alkalinity. pH will follow.
As complicated as this is chemically and biologically (it's way beyond my depth; trust me), it can be ridiculously simple in practice. Add KW drip, either at night or 24x7, as makeup water. If you're not keeping a lot of SPS corals, that's it.
I would recommend the following:
- Read http://www.aquariacentral.com/articles/calcium.shtml
- Read http://www.animalnetwork.com/fish2/aqfm/1998/june/bio/default.asp
- Read http://www.animalnetwork.com/fish2/aqfm/1998/july/bio/default.asp
- Read the Reefkeepers FAQ (at FINS or reefs.org) on this topic
- Search (maybe not post any questions) on RC for alkalinity and pH. Don't be afraid to lurk and read everything.
- Once you get a little more comfortable, do a search for the last name "Bingman." RC, google, wherever you can find. Read it all. I'll look in some printouts I have at home, grab the urls, and post a follow-up note.
Thanks,
Dean