Good Greef Posted August 18, 2015 Share Posted August 18, 2015 Hey everyone, I was hoping I could get some expert help here before trying Reefcentral. In a nutshell, my Mg. level constantly reverts to 1200 ppm from 1300-1350 only 1 week after supplementing with the DIY recipe of Randy Holmes Farley - which calls for a mixture of magnesium cholride and magnesium sulfate using Epsom Salts and BRS Magnesium Chloride. Based on the infamous online calculator, with a net water volume of 65 gallons Im supposed to add 26.5 floz slowly over several hours and never enough to increase by 100pm per day. I test 24 hours later and my Red Sea Pro test kit shows 1350. Either way, in a week it always falls back to 1200. 1. Is this normal? Ive always read that it takes a lot to bring up Mg. but once its up there it maintains fairly constant with water changes. 2. I surmised that it could be low Mg. levels from using Aquavitro Salinity which seems to always be lower in Mg. and Ca. than the stated ranges. So I skipped my 15% weekly WC and the levels still dropped to 1200. 3. Is it possible my corals are consuming this much? I only have mini colonies or frags so I doubt it, but stocking list is: Frogspawn (6 heads) Elegance Coral blastos (20 heads) Trumpet Coral (10 heads) bubble coral purple xenia 2x zoa rocks about the size of a tennis ball Toadstool Mushroom size of softball Devils Hand leather digitata maxima clam Quote Link to comment Share on other sites More sharing options...
Juiceman Posted August 19, 2015 Share Posted August 19, 2015 From what I understand. Corals don't literally take up the MG. MG is used more so to help maintain Alk. I would bet maybe you're skimming it out? Maybe someone else can chime in, but I've never had issues with dropping MG and I don't dose it at all. I have used TechM and BRS MG so maybe its the mixture you're using also? Quote Link to comment Share on other sites More sharing options...
jolt Posted August 19, 2015 Share Posted August 19, 2015 I agree with Juiceman, Mg is not consumed by coral, it is used to allow higher levels of calcium in solution than would naturally occur. I believe there is a process of chemically binding of the mg to calcium which keeps the calcium from precipitating out of the water as calcium carbonate deposits. (see: http://reefkeeping.com/issues/2006-06/rhf/#21) If I had to guess I would say you might use less mg if you dosed less calcium? What is your calcium level? Quote Link to comment Share on other sites More sharing options...
Good Greef Posted August 19, 2015 Author Share Posted August 19, 2015 My calcium levels go from 450 to 375 over the week as well. I dose that with Kent turbo marine calcium, the day after I dose magnesium. It's my understanding that a magnesium of 1300 will help maintain stable calcium and alkalinity levels. Quote Link to comment Share on other sites More sharing options...
FarmerTy Posted August 19, 2015 Share Posted August 19, 2015 Do you happen to use kalkwasser? Or have a ton of coralline algae? Quote Link to comment Share on other sites More sharing options...
Good Greef Posted August 19, 2015 Author Share Posted August 19, 2015 I dont use Kalk. I actually never have to dose alk bc it stays stable around 8dkh through water changes. I do have corraline that covers 90% of my 75g overflow box, and there are patches all over my 100lbs of LR. Quote Link to comment Share on other sites More sharing options...
FarmerTy Posted August 19, 2015 Share Posted August 19, 2015 Only reason I mention coralline because it is a large consumer of Mg by weight. I wish I could add more of my observations from experience but I've never really had to dose Mg because enough is supplied by my Calcium reactor. Quote Link to comment Share on other sites More sharing options...
jolt Posted August 19, 2015 Share Posted August 19, 2015 @Farmer TY: Is a regular weekly drop of 75 in calcium level a lot? It seems large to me, as if there is a lot of precipitation going on ... Good Greef - are you seeing a lot of calcium buildup on your heater, waterline, etc etc? Quote Link to comment Share on other sites More sharing options...
FarmerTy Posted August 19, 2015 Share Posted August 19, 2015 My thoughts were on precipitation as well though even a margin of error on the Ca test kit could be a factor here. My calcium could drop ~40ppm in two days but I also have a SPS dominant tank. 75 ppm drop seems absurd for the current tank inhabitants though I guess it would depend on the size of the colonies/clam. Quote Link to comment Share on other sites More sharing options...
Good Greef Posted August 19, 2015 Author Share Posted August 19, 2015 Jolt - no i dont see much calcium buildup on my heater or waterline. I was thinking it must be precipitating but dont know whats causing it to get to higher levels temporarily. Ty- none of the colonies are huge, so it cannot be the corals consuming it id guess. May be errors on my red sea pro test kits, but its also tough to believe that this "spike then settle" of Ca and Mg has happened consistently weekly over 9 months. I need to read into those hanna testers. Just wanna find a more clear cut measurement of Ca, Mg, Kh that doesnt require color comparisons weekly. Quote Link to comment Share on other sites More sharing options...
jolt Posted August 19, 2015 Share Posted August 19, 2015 Precipitation can also show up as the sand clumping up into balls Most people like the hanna alk tester, I have one I've heard less glowing reviews of the hanna ca tester. I use red sea pro for CA and mg 1 Quote Link to comment Share on other sites More sharing options...
FarmerTy Posted August 19, 2015 Share Posted August 19, 2015 Precipitation can also show up as the sand clumping up into balls Most people like the hanna alk tester, I have one I've heard less glowing reviews of the hanna ca tester. I use red sea pro for CA and mg Took the words right out of my mouth. 1 Quote Link to comment Share on other sites More sharing options...
Juiceman Posted August 20, 2015 Share Posted August 20, 2015 Precipitation can also show up as the sand clumping up into balls Most people like the hanna alk tester, I have one I've heard less glowing reviews of the hanna ca tester. I use red sea pro for CA and mg Took the words right out of my mouth. what he said Quote Link to comment Share on other sites More sharing options...
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