Let's talk about Alkalinity, Calcium and Magnesium in an SPS Tank
- Thread starter JB NY
- Start date
Aquarist007
New member
<a href=showthread.php?s=&postid=12788420#post12788420 target=_blank>Originally posted</a> by gary faulkner
Capn,
Sounds Greek to me too.
I wasn't kidding---I did follow the drift--Mcsaxmaster does explain chemistry well:smokin:
MCsaxmaster
New member
ULNS?
MCsaxmaster
New member
I've heard complaints of recession when alkalinity is higher than ~8 dKH from people using zeovit systems, but I'm not sure I've heard of it elsewhere. I've heard of this phenomenon from enough people to suspect something is going on, but it's not clear what. I don't see any reason to expect a reaction like that when alkalinity is elevated to that level. If you raise alkalinity in NSW (e.g., w/NaHCO3), corals grow faster, and they don't experience recession. Lots and lots of people, myself included, have maintained higher alkalinity in captivity for years with good success. If there really is a problem associated with higher alkalinity there, it strikes me as a problem with the system, but an unusual one to be sure.
Also, I'm not sure that a term like "ultra low nutrient system" is apt for systems that doses organic C sources. Some of these systems may indeed achieve low dissolved inorganic N and P in the water column, but that can be achieved with other systems as well. Also, simply because organic C is dosed, or zeolites are used, or whatever else and the intention is to have very low DIN and DIP does not mean that one actually achieves such conditions. Without some good nutrient measurements, one really cannot say what nutrient levels are like at the low end of things, except to say lower than the detection limit on their test kits. The water overlying a typical coral reef will pretty much always have undetectable nutrient levels though. But, to be fair the corals are not actually in contact with that water--they are in contact with water in several boundary layers overlying the reef, where dissolved nutrients can be up to several orders of magnitude higher than in the overlying water. Corals also tend to eat a lot of zooplankton/pseudoplankton in nature, so they have access to a lot more in the way of N and P than we might often appreciate.
Chris
tyreeftank
New member
I have 75g tank:
Calcium = 160 ppm
magnesium = 900 ppm
alk = 12 dkh
ph=8.2.
I need to increase my calcium and magnesium. Do I increase my magnesium first then calcium? I manage to increase my magnesium to 1000 ppm now. Should I start adding calcium as I adding magnesium?
Calcium = 160 ppm
magnesium = 900 ppm
alk = 12 dkh
ph=8.2.
I need to increase my calcium and magnesium. Do I increase my magnesium first then calcium? I manage to increase my magnesium to 1000 ppm now. Should I start adding calcium as I adding magnesium?
melev
Well-known member
You can definitely start adding more calcium to the water, assuming that test result is correct. It seems quite low. Which tank is this test for? The 150g or the 75g? A big healthy water change should help bring that up to normal levels, usually (depending on the brand of salt you use).
You might have your LFS (local fish store) test your water to compare their results to yours.
You might have your LFS (local fish store) test your water to compare their results to yours.
tyreeftank
New member
This is for my 75g tanks. My LFS test my Mg and Calcium for me, since I dont have Mg test kit. I compare the Calcium result from my LFS with my test kit and it match. I dont know with it soo low. I was told that since my Mg is so low, I will not be able to increase my Cal until my Mg is at a reasonable level. I will try to add calcium and see if it change. Thanks for the advise.
melev
Well-known member
It is true that they work together. Raising the Mg will help. The target range is in a few of Randy's articles.
Cal - 370 to 425
Alk - 8 to 11 dKH
Mg 1300 or more (my preference)
Mg should be 3x the calcium reading. So it shouln't be tough to bring it up to 300ppm at least, pretty much double what you have now. I just think the reading is false, unless...
If you are dosing calcium, don't just dump it in. Pour it in very gradually into an area of strong flow so it doesn't turn to a solid. You don't want to see snowflakes in the water.
If you are making your own saltwater, add the salt to a barrel of water. Do NOT put the salt in the bucket first, then add the water as it will precipitate out. This is discussed in this article briefly:
http://reefkeeping.com/issues/2007-11/nftt/index.php
Cal - 370 to 425
Alk - 8 to 11 dKH
Mg 1300 or more (my preference)
Mg should be 3x the calcium reading. So it shouln't be tough to bring it up to 300ppm at least, pretty much double what you have now. I just think the reading is false, unless...
If you are dosing calcium, don't just dump it in. Pour it in very gradually into an area of strong flow so it doesn't turn to a solid. You don't want to see snowflakes in the water.
If you are making your own saltwater, add the salt to a barrel of water. Do NOT put the salt in the bucket first, then add the water as it will precipitate out. This is discussed in this article briefly:
http://reefkeeping.com/issues/2007-11/nftt/index.php
tyreeftank
New member
Well after some water change, dosing with Kent Turob Calcium, Kent Tech-M, and 2.5 lb of Epsom Salt, my water parameters are as follow:
Cal - 400
Alk - 10 dkH
Mg - Not test yet. From my estimate values from dosing with Tech-M and Epsom Salt. It probably 1400. Hopefully it stay this way. I also start running my Kalk Reactor as my auto top off.
Cal - 400
Alk - 10 dkH
Mg - Not test yet. From my estimate values from dosing with Tech-M and Epsom Salt. It probably 1400. Hopefully it stay this way. I also start running my Kalk Reactor as my auto top off.
Torpus
New member
I just started added Mg to my 40g tank. I'm only adding 1tsp every third day instead of the perscribed 2tsps twice a week per 20g as recommended on the container because testing showed decent mg levels of 1200-1300 and I wanted to slowly raise it up to around 1400-1500.
My question is, has anyone had any bleeching as a result of starting to use Mg? I have one plating monti that started slowly bleeching right about when I started using Mg. There is no scientific evidence to show that the Mg is what is causing the bleeching in my tank besides timing, but the coral was doing really well until around the time I started adding the Mg.
My question is, has anyone had any bleeching as a result of starting to use Mg? I have one plating monti that started slowly bleeching right about when I started using Mg. There is no scientific evidence to show that the Mg is what is causing the bleeching in my tank besides timing, but the coral was doing really well until around the time I started adding the Mg.
Aquarist007
New member
why are you bringing the mag level up to 1400-1500--it really only needs to be around 1300ppm
Are you adding the mag directly to the sump or display tank--I would try mixing it first in a separate container and then adding it to the tank.
Aquarist007
New member
thanks for the tip
