Pound of magnesium
- Thread starter BioMan
- Start date
- Location
- Queens
I found this page that says 1 cup of magnesium weighs about .9 pounds. I really dont know but that number seems incredibly high to me.
http://www.aqua-calc.com/calculate/volume-to-weight
Interestingly enough, in an effort to cut down the time required for water changes, I started weighing my salt recently. I found that 766 grams of salt makes 5 gallons at somewhere between 1.023 and 1.025 (it varies a little bit). Given that number, 100 gallons would have 15,320 grams of salt, which is about 34 pounds.
http://www.aqua-calc.com/calculate/volume-to-weight
Interestingly enough, in an effort to cut down the time required for water changes, I started weighing my salt recently. I found that 766 grams of salt makes 5 gallons at somewhere between 1.023 and 1.025 (it varies a little bit). Given that number, 100 gallons would have 15,320 grams of salt, which is about 34 pounds.
- Location
- Queens
Yes, that's what I use. The orange bag. Their rating is at 1.021 though... marketing and all, so it would probably be slightly less than 17 pounds. When i get a new bag, I measure the whole thing out into ziplock bags all at once. It saves me a lot of time doing it that way.
- Location
- Duluth, Minnesota
Bio
Yes that is correct, about 1 lb
52.7 mmol/ Kg X 24.305 grams = 1,280 Mg / l X 378.54 = 484,531 mg = 1.068 lbs.
Yes that is correct, about 1 lb
52.7 mmol/ Kg X 24.305 grams = 1,280 Mg / l X 378.54 = 484,531 mg = 1.068 lbs.
- Location
- Duluth, Minnesota
Zip
I forgot, the reason your mix weight is about +10 % to high is some salt mixes have salt components of water which adds to the weight verses a 100 % dry mix, of which there is no such thing. Best I have seen is about 1% water. You are around 40 grams rather 35 grams.
I forgot, the reason your mix weight is about +10 % to high is some salt mixes have salt components of water which adds to the weight verses a 100 % dry mix, of which there is no such thing. Best I have seen is about 1% water. You are around 40 grams rather 35 grams.
- Location
- Queens
So you are saying that my weight measurements are going to be inconsistent from bag to bag of salt. That makes sense, and I was thinking that would probably be true. That also explains why some of my buckets are closer to 1.023 and others closer to 1.025. Looks like i just need to start buying 200 gallon bags 
Thanks!
Thanks!
- Location
- Duluth, Minnesota
You may have misunderstand what I said by your weight 40 vs 35. I should have explained it in detail.
Seawater Salinty is 35 ppt, that means 35 grams of salt dissolved in 1 kg of water.
So, 965 mg or 965 ml is water and 35 grams is the weight of all the stuff, salts, dissolved.
If you weighed out 35 grams and added it to 965 grams or 965 ml of water and then tested the Salinity you will NOT get 35 ppt. It will measure from 29 ppt to 34.?? ppt. So, where did it go ? That say 1-6 ppt is missing. And that 1-6 ppt is there but it is water not salt. A number of salts in the salt mix have water attached to them. The reason is a manufacturer can make them easier, less costly and to add when you add the salt to the water the water does not heat up so much, called a exothermic reaction. Lastly, some of the chemical corporations that make the salts that all the aquarium salt companies use have more than one process to make say MgCl2 (see below). These processes can have to much of say a contaminant WE don't want. Some MgCl2 's can be high or low in Ammonia and /or Lithium. Our salts, well, we don't know what the hell we have unless somebody wants to pay for a XRD assay of the dry mix in the bag or make up a solution mix to 35 g / kg and run it through a ICP. ICP has been done for us in the past but years ago and often aquarium salt mixes change as they change them but don't tell you when and what is changed. So, you get what you get. Besides it really makes no DAM difference which one you use. It is pure gibberish nonsense that one is better than another, other than sales hype. There is no such thing anywhere, that shows that aquarium salt A is better than B in ANY study, as there has never been one done. And when I say better the only thing that counts are the animals. And if some reefer says I switched salt brands and things are better he/ she does NOT understand WHY that SEEMS to have happened. Meaning, it is not the mix per say it is A is slightly different than B and you pissed off or made some animal more happy, as you changed what they are use to and many animals don't like changes unless done very slowly over time. You would get the same, if you did a large WC with your B. There is no magic in the bag. Reefers and aquarium companies make up all kinds of stuff they don't understand and often you don't need.
Ok let's look a Mag- Chloride
MgCl2-6H2O
So, in that example, 1 lb. of that salt will be ~ 1/2 lb. of salt (MgCl2) and ~ 1/2 lb. of water.
Now if only that salt is used you are kinda ok but if they say blend that salt for what ever reason such as
MgCl2, MgCl2-2H20, MgCl-6H2
Now, during say the bagging or you do not seal it properly it will pick up moister and will be worse.
Seawater Salinty is 35 ppt, that means 35 grams of salt dissolved in 1 kg of water.
So, 965 mg or 965 ml is water and 35 grams is the weight of all the stuff, salts, dissolved.
If you weighed out 35 grams and added it to 965 grams or 965 ml of water and then tested the Salinity you will NOT get 35 ppt. It will measure from 29 ppt to 34.?? ppt. So, where did it go ? That say 1-6 ppt is missing. And that 1-6 ppt is there but it is water not salt. A number of salts in the salt mix have water attached to them. The reason is a manufacturer can make them easier, less costly and to add when you add the salt to the water the water does not heat up so much, called a exothermic reaction. Lastly, some of the chemical corporations that make the salts that all the aquarium salt companies use have more than one process to make say MgCl2 (see below). These processes can have to much of say a contaminant WE don't want. Some MgCl2 's can be high or low in Ammonia and /or Lithium. Our salts, well, we don't know what the hell we have unless somebody wants to pay for a XRD assay of the dry mix in the bag or make up a solution mix to 35 g / kg and run it through a ICP. ICP has been done for us in the past but years ago and often aquarium salt mixes change as they change them but don't tell you when and what is changed. So, you get what you get. Besides it really makes no DAM difference which one you use. It is pure gibberish nonsense that one is better than another, other than sales hype. There is no such thing anywhere, that shows that aquarium salt A is better than B in ANY study, as there has never been one done. And when I say better the only thing that counts are the animals. And if some reefer says I switched salt brands and things are better he/ she does NOT understand WHY that SEEMS to have happened. Meaning, it is not the mix per say it is A is slightly different than B and you pissed off or made some animal more happy, as you changed what they are use to and many animals don't like changes unless done very slowly over time. You would get the same, if you did a large WC with your B. There is no magic in the bag. Reefers and aquarium companies make up all kinds of stuff they don't understand and often you don't need.
Ok let's look a Mag- Chloride
MgCl2-6H2O
So, in that example, 1 lb. of that salt will be ~ 1/2 lb. of salt (MgCl2) and ~ 1/2 lb. of water.
Now if only that salt is used you are kinda ok but if they say blend that salt for what ever reason such as
MgCl2, MgCl2-2H20, MgCl-6H2
Now, during say the bagging or you do not seal it properly it will pick up moister and will be worse.
Last edited:
- Location
- westchester
Will this be on the final exam?
Got to love science.
Now I'm sure someone is going to comment on how much better there salt is now that they switched from whatever brand they were using. The salt mixes so much quicker. It's much clearer. There's no residue. So much more growth and extension. Fish are now smiling
I would think there would of been some sort of testing of sats by now. This is a big hobby now. These brands would have to have some claims in order to mark there prices so high in comparison to other salt brands or are we all just that naive and beleive any and everything they say?
Now I'm sure someone is going to comment on how much better there salt is now that they switched from whatever brand they were using. The salt mixes so much quicker. It's much clearer. There's no residue. So much more growth and extension. Fish are now smiling
I would think there would of been some sort of testing of sats by now. This is a big hobby now. These brands would have to have some claims in order to mark there prices so high in comparison to other salt brands or are we all just that naive and beleive any and everything they say?
- Location
- Duluth, Minnesota
Diver :lol:
If you read it no exam :wink1:
If you read it no exam :wink1:
- Location
- Duluth, Minnesota
Marketing hype b. These tests are not cheap, a few thousand dollars and need to be done independently not by some aquarium manufacturer.
I don't think I have heard the smiling fish one yet,that was funny. In the last 20 years 4 salt assays and 3 of those were all done around 2005. The thing is you HAVE TO HAVE it done where they NOW how to test a sea mix. Seawater testing is nowhere near as easy as FW, as all these ions mess up testing procedures. Your pH meter and most pH test kits are way off. We tell you that NSW pH is 8.3 but in reality it is really 8.15 because that is how much the salt causes the pH error. You calibrate that meter in a FW pH std. Nobody sells pH stds for seawater.
So, to be clear as some take this and run with in the wrong direction:
My meter is calibrated in the std I got. I tested my tank water and the meter says 8.3 and the error is -0.15
8.3 - 0.15 = 8.15. Ok I am good NSW is really 8.15.
A pH test kit can be off from -0 - 0.5 error depending on the pH solution where there're crap loads of them. This is why I often chuckle when somebody claims test kit A is a crappy kit and is way off, when in fact that test kit is right on and that meter is off.
I don't think I have heard the smiling fish one yet,that was funny. In the last 20 years 4 salt assays and 3 of those were all done around 2005. The thing is you HAVE TO HAVE it done where they NOW how to test a sea mix. Seawater testing is nowhere near as easy as FW, as all these ions mess up testing procedures. Your pH meter and most pH test kits are way off. We tell you that NSW pH is 8.3 but in reality it is really 8.15 because that is how much the salt causes the pH error. You calibrate that meter in a FW pH std. Nobody sells pH stds for seawater.
So, to be clear as some take this and run with in the wrong direction:
My meter is calibrated in the std I got. I tested my tank water and the meter says 8.3 and the error is -0.15
8.3 - 0.15 = 8.15. Ok I am good NSW is really 8.15.
A pH test kit can be off from -0 - 0.5 error depending on the pH solution where there're crap loads of them. This is why I often chuckle when somebody claims test kit A is a crappy kit and is way off, when in fact that test kit is right on and that meter is off.
- Location
- Brooklyn
Boomer
Thanks for the thorough explanation, and for shedding some light on a highly debated topic. I am wondering why some salts mix to different ALK and Ca levels. I am currently using a salt that is high in alkalinity and I want to use something that mixes to lower numbers. I have tried this in the past and found that ALK levels of newly mixed water were much higher than advertised. Im thinking maybe it is because I tested water that was freshly mixed and it needed time to stabilize?? I have read that Ph fluctuates in newly mixed water I imagine this would affect alkalinity... I see you state that it makes no difference which salt you use. Should we ignore the levels of the freshly mixed salt? Are these levels something we should take into consideration when selecting a salt? Thanks in advance for your time and expertise.
Thanks for the thorough explanation, and for shedding some light on a highly debated topic. I am wondering why some salts mix to different ALK and Ca levels. I am currently using a salt that is high in alkalinity and I want to use something that mixes to lower numbers. I have tried this in the past and found that ALK levels of newly mixed water were much higher than advertised. Im thinking maybe it is because I tested water that was freshly mixed and it needed time to stabilize?? I have read that Ph fluctuates in newly mixed water I imagine this would affect alkalinity... I see you state that it makes no difference which salt you use. Should we ignore the levels of the freshly mixed salt? Are these levels something we should take into consideration when selecting a salt? Thanks in advance for your time and expertise.
- Location
- Duluth, Minnesota
BKLN
The original reason why some salts are so high was many reefers had two reasons
1. I want a salt mix where I don't have to add any sups. So, say they want the calcium to get no lower than 425 ppm. Use salt that gives 480 ppm, let the calcium drop to 425, do a water change to bring it back up. There logic is if the salt was 425 you need to add sups to keep it there. This WC idea is a bad idea as the levels are constantly changing making their environment unstable.
2. Salt with high calcium and Alk makes corals grow faster. No. Corals have no use for calcium more than ~ 370 or so. 450, 490, does not make corals grow faster. The high Alk is just for ionic balance. However, just high Alk does make them grow faster. But there is also making them grow to fast. There is often the impression fast growing corals are a sign of health. No it is not if they grow to fast. To high growth rates can cause two things.
1. It lowers the skeletal density of aragonite, which makes the skeleton more brittle and subject to breakage.
2. What some call Alk Burn, which has nothing to do with Alk burning anything. Fast growth rates thins out the tissue, especially at the tips where corals grow the fastest, where the tissues is the thinnest making it tear very easily at the tips. So called Alk burn. The true health of a coral is the health of the tissue not how fast its skeleton grows in size and thin tissues is not healthy. Myself and Mojo Reef have had this theory for years. There is now some recent research that shows this may be true.
Many, many salts have been tested in the past by ICP and even test kits that show period and quite often the bag does not have what it claims. There are reasons for this at times where the quality control may vary from one day to the other. The reefer himself by not mixing the dry mix before he uses it, by making up the salt mix solution to fast by the mixing procedures he is using.
pH fluctuations come from some of the same, mixing and variations in the room air CO2 and the buffers they use to get a pH and Alk. I don't care if it is Bob's, Dick's or Jane's salt that if all 3 have a pH of 8.1 the ratio of CO3 to HCO3 is exactly the same. They may differ slightly in Alk at the same pH or one manufacturer adds more or less Borate. Any of these, we will say, makes A looking better than B on a data sheet but is vey short lived unless you are one that does lots of water changes.
I always tell people use the salt that best suits you and your needs.
The best way to mix a salt the fastest and with the fastest equilibrium, is to
1. Throughly mix the dry salt first.
2. Add salt to the water slower
3. Have the mixing water slightly cooler.
3. Use a drill powered paint mixer bit.
You can actually mix a ^^ 50 gal batch in 5 min this way
The original reason why some salts are so high was many reefers had two reasons
1. I want a salt mix where I don't have to add any sups. So, say they want the calcium to get no lower than 425 ppm. Use salt that gives 480 ppm, let the calcium drop to 425, do a water change to bring it back up. There logic is if the salt was 425 you need to add sups to keep it there. This WC idea is a bad idea as the levels are constantly changing making their environment unstable.
2. Salt with high calcium and Alk makes corals grow faster. No. Corals have no use for calcium more than ~ 370 or so. 450, 490, does not make corals grow faster. The high Alk is just for ionic balance. However, just high Alk does make them grow faster. But there is also making them grow to fast. There is often the impression fast growing corals are a sign of health. No it is not if they grow to fast. To high growth rates can cause two things.
1. It lowers the skeletal density of aragonite, which makes the skeleton more brittle and subject to breakage.
2. What some call Alk Burn, which has nothing to do with Alk burning anything. Fast growth rates thins out the tissue, especially at the tips where corals grow the fastest, where the tissues is the thinnest making it tear very easily at the tips. So called Alk burn. The true health of a coral is the health of the tissue not how fast its skeleton grows in size and thin tissues is not healthy. Myself and Mojo Reef have had this theory for years. There is now some recent research that shows this may be true.
Many, many salts have been tested in the past by ICP and even test kits that show period and quite often the bag does not have what it claims. There are reasons for this at times where the quality control may vary from one day to the other. The reefer himself by not mixing the dry mix before he uses it, by making up the salt mix solution to fast by the mixing procedures he is using.
pH fluctuations come from some of the same, mixing and variations in the room air CO2 and the buffers they use to get a pH and Alk. I don't care if it is Bob's, Dick's or Jane's salt that if all 3 have a pH of 8.1 the ratio of CO3 to HCO3 is exactly the same. They may differ slightly in Alk at the same pH or one manufacturer adds more or less Borate. Any of these, we will say, makes A looking better than B on a data sheet but is vey short lived unless you are one that does lots of water changes.
I always tell people use the salt that best suits you and your needs.
The best way to mix a salt the fastest and with the fastest equilibrium, is to
1. Throughly mix the dry salt first.
2. Add salt to the water slower
3. Have the mixing water slightly cooler.
3. Use a drill powered paint mixer bit.
You can actually mix a ^^ 50 gal batch in 5 min this way
Last edited:
- Location
- Queens
Hi. Good info.
I use instant ocean with Rodi water at 0 ppm. My pH is typically about 8 to 8.1, alk is about 10. Calcium is usually about 500... So this must be one of those high alk high calcium mixes you mentioned. I've only tested for magnesium from my tank,not immediately after a water change but I think my magnesium was around 1400. I do realize these values for calcium and magnesium are a tad high, but that's just what I get from the crystals.
When I mix my water, I typically throw a 600 gph pump in the bucket, then pour the salt in. I've found that if I pour the salt in too quickly, the water is cloudier. My understanding is because a higher salt content raises the PH temporarily when the salt is poured in, and the higher PH causes the calcium to precipitate (I think thats the correct word). I've found if i pour it in more slowly the water clears up quicker.
Usually i leave the pump running in the bucket for about 10 to 15 minutes, and I'll keep the mixed water on hand for up to 2 weeks until my next water change. I notice sometimes there is some sludgy orangy\brown stuff at the bottom. I assume its calcium. I'm using the 5 gallon homer buckets and i was wondering if the orange\brown was from the bucket but everyone says they use these homer buckets just fine and its no problem. I wash the buckets out after water changes just in case.
I use instant ocean with Rodi water at 0 ppm. My pH is typically about 8 to 8.1, alk is about 10. Calcium is usually about 500... So this must be one of those high alk high calcium mixes you mentioned. I've only tested for magnesium from my tank,not immediately after a water change but I think my magnesium was around 1400. I do realize these values for calcium and magnesium are a tad high, but that's just what I get from the crystals.
When I mix my water, I typically throw a 600 gph pump in the bucket, then pour the salt in. I've found that if I pour the salt in too quickly, the water is cloudier. My understanding is because a higher salt content raises the PH temporarily when the salt is poured in, and the higher PH causes the calcium to precipitate (I think thats the correct word). I've found if i pour it in more slowly the water clears up quicker.
Usually i leave the pump running in the bucket for about 10 to 15 minutes, and I'll keep the mixed water on hand for up to 2 weeks until my next water change. I notice sometimes there is some sludgy orangy\brown stuff at the bottom. I assume its calcium. I'm using the 5 gallon homer buckets and i was wondering if the orange\brown was from the bucket but everyone says they use these homer buckets just fine and its no problem. I wash the buckets out after water changes just in case.
- Location
- Brooklyn
Boomer
Thanks for taking the time to answer my questions. I appreciate it.
Thanks for taking the time to answer my questions. I appreciate it.
- Location
- Duluth, Minnesota
Kinda half right on the mixing. When you pour in the salt mix there is why we call the " local area". That is the area of water the salt occupies when you pour it in, especially to fast. The concentration in the local area is verrrrrrry high in everything. That loca area is over saturated with the salt and all kinds of things happe. Example: the high pH, high Alk, high calcium are so high the calcium and Alk leave solution as a solid of CaCO3, think limestone and it doesn't redissolve. Another is Magnesium hydroxide, Mg(OH)2, think magnesium based Kalk but this form doesn't dissolve like Kalk. That cloudy water you speak of is these and ends up on the bottom or walls as a coating, think hard water deposits or dust.
The sluggy stuff is often carries and or binders that are used to add certain ions to the water. These carriers are a times clay minerals. Pretend you have a prescription of 10 mg but that dam pill is the size of a aspirin tablet, you weight it and it is says 200 mg. Well, you can't see 10 mg per say, it would be like a grain of sand. So, many pills have the drug embedded in binders/ carries. Look at a aspirin tablet and think how big 10 mg would be. A aspirin is 325 mg. That is 1/32 of a aspirin tablet. In some salts you will find actual sand grains that have entered some storage facilities and get into the salt. Red Sea has had this issue at times.
500 ppm, is waaaaaay off from any past testing on IO. IO is known for being one of the lowest of all salt mixes. Their Alk is about what you got. Get some friend or LFS to test this batch with their test kit for calcium. If one bag, we will say, bad bag, but many bags waaaaaaay wrong, unless you have had bad luck and got the same lot # from a bad batch. Long ago their was a bad batch of a salt mix where the Alk was 20 dKH.
The sluggy stuff is often carries and or binders that are used to add certain ions to the water. These carriers are a times clay minerals. Pretend you have a prescription of 10 mg but that dam pill is the size of a aspirin tablet, you weight it and it is says 200 mg. Well, you can't see 10 mg per say, it would be like a grain of sand. So, many pills have the drug embedded in binders/ carries. Look at a aspirin tablet and think how big 10 mg would be. A aspirin is 325 mg. That is 1/32 of a aspirin tablet. In some salts you will find actual sand grains that have entered some storage facilities and get into the salt. Red Sea has had this issue at times.
500 ppm, is waaaaaay off from any past testing on IO. IO is known for being one of the lowest of all salt mixes. Their Alk is about what you got. Get some friend or LFS to test this batch with their test kit for calcium. If one bag, we will say, bad bag, but many bags waaaaaaay wrong, unless you have had bad luck and got the same lot # from a bad batch. Long ago their was a bad batch of a salt mix where the Alk was 20 dKH.
- Location
- Queens
I just looked up the numbers that I had written down, and you're absolutely correct. My numbers came back around 460 rather than 500. I've been measuring my tanks for the last few months deciding that 23 "drops" of the second bottle in my tests means its ok. Turns out that 23 drops is 460 (ppm?) of calcium.
I thought I had a good idea of the chemistry of this, but I could learn a lot from you boomer. I'm not so sure that I have the brain cycles to pick it all up though.
I thought I had a good idea of the chemistry of this, but I could learn a lot from you boomer. I'm not so sure that I have the brain cycles to pick it all up though.
- Location
- Duluth, Minnesota
Ok better but for decades IO was ~ 380 and then a few years ago they bumped it up to around 410. For decades when it ran around 380 they claimed 420, it finally got to them after all the complaints. 460 is still high for IO.
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