Anthony Calfo outlined a Synthetic SW Mixing method that suggests that it is important to properly aerate (24 hours) and buffer your purified water before adding salt:
I am curious to know if how many TR members do this. I have not been aerating my RODI water prior to mixing my SW. I may try this to see if it helps the resulting levels of pH, Alk, Ca, and Mg after mixing and aerating the salt solution.
I have a deep respect for my friend Anthony Calfo. My assessment of that topic is different than his. I have not achieved the fame and fortune that Anthony has but, I have used hundreds of the 200 gal IO brand of salt in the last 41 years and several dozen buckets of other brands, too. In fact, I have ten 200 gal buckets of IO in my garage (probably the last remaining 200 gal buckets of IO in the world) just waiting to be mixed for the aquaculture project. My method of mixing goes like this. I keep 4 55 gallon barrels of RO/DI water on hand out side, full and capped off. I move 35 gallons into a Brute container in the house. I then plug in a Mag 2400 pumping the water up from the bottom into a 100 micron filter sock. The salt goes in immediately from a 200 gallon bucket. The salt settles to the bottom and I stir it every little while until dissolved. I check salinity, pH, Calcium and Magnesium. Depending on how quickly I need the water, I may use it immediately or let it mix through the filter sock till the next day. If I need to adjust anything it's salinity, Calcium and Magnesium. This has worked for me through 41 years of being a marine hobbyist.
I love Anthony, he is a wise and generous man. I think in that thread he's trying to split hair finer than frog hair.
Dick
__________________ Amphibious
Reaching my 70th BD, I realize that I cannot help but grow old. However, I refuse to grow up!!! My wife would tell you, "He may be 70 but, He's going on 17". Life is wonderful with a woman like that.
I then plug in a Mag 2400 pumping the water up from the bottom into a 100 micron filter sock.
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I love Anthony, he is a wise and generous man. I think in that thread he's trying to split hair finer than frog hair.
Thanks Amph. Understood. Calfo has zeal and insight, but sometimes he seems like the "shock jock" of the reef keeping world.
One of my main motivators for finding a better method is because I have already tested 2 buckets of Reef Crystals to be low in Ca, and a small bucket of Coral Pro to be lower in Alk and Mg than has been generally tested/reported. Even though F&S confirmed my RC results, and Coral Pro has the Ca level I was looking for, I cannot help but suspect that my method could be improved.
Is it not without reason that a low pH in purified water could compromise the way that Ca is dissolved into solution? Also, as an aside, wouldn't there be a benefit to having the purified water heated to tank temp before adding salt? Perhaps it doesn't matter how fast things dissolve, but after reading a few Randy Holmes-Farley articles with enough formulae to make my eyes tear, I come away thinking that these ionic balances are quite tenuous.
BTW: What is the sock for? Catching impurities in the mix?
I know you and others have had problems lately with the RC brand of salt. If I'm not mistaken, didn't someone buy Aquarium Systems a few years ago? If so, a lot of times a new owner is not committed to quality control as the originator and more interested in tweaking out more profit. I'm not sure that is the case at all, just suspicious.
There's very little Chemist in me so, your question about low pH in purified water compromising Ca's dissolution into solution will necessarily go unanswered. Sorry! There might be a benefit to warming the water to tank temp prior to adding salt in that it would dissolve quicker/better/more thoroughly. Don't know for sure as my water stored outside comes in quite warm and my mixing/dissolving is done quickly.
The sock was put into use when I began collecting NSW. I would "filter" the NSW for 48 hours through the sock. Interesting how the NSW "looked" so clean and how the sock would "dirty-up" in that time. Not sure what it was taking out but, I felt like I was doing the right thing. I collected seven miles do East of the Fort Pierce Inlet. WHY SEVEN MILES??? Easy, lucky number, I could still see FL to the West of me, the water looked crystal clear and the first time I collected, it was at the seven mile mark according to my GPS, about twenty feet down was a Hawksbill turtle. I shut the engine down, turned the poat around and he surfaced about 40' away. Then, off he went. That was an Omen of some kind. I marked the GPS with "Water Source" and that became the go to spot.
Collect and using NSW was never about economics. It was always about using the "real thing". Now with fuel over $4 a gallon we seldom go out. Of course we are concentrating on the building right now. I'm sure we'll do some NSW collecting when that's done.
Dick
__________________ Amphibious
Reaching my 70th BD, I realize that I cannot help but grow old. However, I refuse to grow up!!! My wife would tell you, "He may be 70 but, He's going on 17". Life is wonderful with a woman like that.
Ah, I was going to ask about the filter sock! Good reason to have one!
As far as chemistry and heat helping mix goes I havent noticed a chemistry change in any of my methods regardless. I used to mix in 5 gallon buckets a few hours prior to water changes, I now have a 20 gallon rubbermaid tub with a powerhead and heater running in the closet. I'll fill the tub up, and add salt as I wander by here and there until I reach the proper salinity. The heater is to bring the water up to tank temp to avoid shock during water change but it does help to aid the mixing process as well.
FWIW in the hair splitting arguments about letting sw sit I havent noticed any chemical changes over time either. I've had buckets of mixed SW sit for upwards of 4 weeks with no noticeable changes. Thats not to say that a chemical change hasnt taken place as I'm not testing down to the micromole or running my water through a spectrometer. But aside from labor, spills/cleanliness, and space issues I've yet to see any negatives to either method.
I am currently testing a new method dubbed "the nephew maintenance method" whereby I have my 5 year old nephew prepare my water for me ahead of time... so far it's been fairly decent with no effort on my part to mix an endless supply of mixed SW but sometimes the salinity is a little off. I'm not sure how feasible this method is as I have yet to obtain market pricing on new and/or replacement nephews suggesting to me that most LFS simply dont carry them for some reason... and since this tool only appears at my house occasionally it's been hit or miss as to whether or not he's ready when I need mixed SW. I'll keep you posted.
__________________ ~J
because it's all about the plankton
The Following User Says Thank You to THEJRC For This Useful Post:
Good thread. I have made and used SW within 60 minutes and I have let it mix for a week. I have also pre-mixed it overnight by mistake when I have dropped in the powerhead, gotten distracted and forgotten to go back and dump in the salt. I can't say that I have noticed any difference in the methods.
My preferred method is to dump water into my Brute, start the powerhead and then dump in the initial bolus of salt. I go back after an hour or so, check the SpG, add salt and repeat as needed. I prefer to let it mix overnight just because I cannot test for every element and I believe that some are slower dissolving than others. Why overnight? It's arbitrary. I have found that the Rio 2500 that I use for mixing salt creates enough heat that I don't need a heater to get the water up to tank temperature unless I am mixing 20 or more gallons.
My preferred method is to dump water into my Brute, start the powerhead and then dump in the initial bolus of salt. I go back after an hour or so, check the SpG, add salt and repeat as needed. I prefer to let it mix overnight just because I cannot test for every element and I believe that some are slower dissolving than others.
Thanks Carmie. My method is similar, except I measure exactly 750 grams of salt using a digital scale, which puts me spot on when I double check the SG. My pump of choice is a Maxijet 900 with a Sure Flow propeller kit, since I had one that I wasn't using. Does well to churn up the water.
However, my last batch I did in a 5g food-safe bucket (instead of my Brute), and I churned and heated the RODI water (lid off) for 12 hours before adding the salt. The results were the same for every parameter except Alk. Last time I double-tested the Coral Pro salt at 7 dKH. This time it was 9 dKH, just as Bobby has indicated. Unfortunately, the Mg in this Coral Pro bucket is still low, as it tests virtually the same (870 ppm - Salifert) it did last time.
Is it odd that the Ca can be so high when the Mg is so low?
I useually set up a 25gal rubbermade tube at RO/DI water and salt. turn on my RIO 2500 pump and let it mix for usually 8-10 hours. Check the SG adjusted as needed. drain tank, connect hose to pump and pump water into tank. This has worked well for me so far.
Scott, interesting observation about the alk. I think that the Mg-Ca imbalance you are experiencing may be due to poorly mixed dry ingredients (at the factory).
Scott, interesting observation about the alk. I think that the Mg-Ca imbalance you are experiencing may be due to poorly mixed dry ingredients (at the factory).
I am actually hoping that my Mg kit may be out of whack, because I really like the Coral Pro salt otherwise. I am going to be purchasing another Mg kit (perhaps Elos, any other recommendations other than Salifert for Mg kits?) to verify. Alternatively, I'll could track down a reference solution recipe for Mg to validate my Salifert kit.
I can't say that I have noticed any difference in the methods.
I have found that the Rio 2500 that I use for mixing salt creates enough heat that I don't need a heater to get the water up to tank temperature unless I am mixing 20 or more gallons.
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