I have seen on BRSTV that some salt mixes break down and the calcium, alkalinity do not stand up if mixed and let to sit for long periods of time, but for the most part most commercial salt mixes hold up pretty good when you mix and let them set for long periods of time. When I am going to do a water change I usually mix my salt 24-48 hours prior to using it and make about 3 gallons more than what I am going to be using just in case I need more. I use Instant Ocean Reef Crystal salt mix. I have a 125 gallon which is currently cycling but when I need to do water changes I will do 20% every two weeks if needed or 40% monthly. I know there are people out there that never do water changes and I think that is great and usually works on well established larger tanks.Why would a salt solution break down? It's a chemical solution and until you add organics it shouldn't change.
My mixing pump is set to circulate for 15 minutes every 4 hours. That seemed to help with my last 2 water changes, as mixed salt sat for more than 1 1/2 weeks in both cases. After 15 gallon change Alk decreased from 9.79 to 9.66, Ca remained the same at 407ppm, and Mg dropped from 1433 to 1413. All of these changes were less drastic than when I mix and let sit. Using Red Sea Coral Pro.Does anyone circulate the stored salt water until it is used?
I do worry a bit as Aquaforest Reef Salt (that i will not use in the future) has amino acids and vitamin C if I recall correctly
It may depend of the storage container used. Is it plastic ( polymer containing usable carbon) on which bacteria like to grow? In the case bacteria will grow fast and consume what they can from the mix. Was the container previously used for something else, for example to store used aquarium water? Was the container properly disinfected ? The mix is best stored in the dark, also photo-autotrophs may grow , produce protein and use from the saltmix, cycling the content of the container.
Most salt mixes contain a limited amount of nitrogen and phosphorus which limits the growth. In the case, how suitable is a standard salt mix for cycling a new tank?
Mixed salts ready to be used, it will not take long for the mix to contain some organics which will be cycled.
A salt mix stored ready to use, a lot of the usable content may have been stored in organics.
Dissolving salts, store the mix at high concentration, if necessary.
Hypersaline? It is the intention the salts stay in solution. Also depending on the mix used.IMO, that is a poor plan.
Trying to make hypersaline artificial seawater can easily result in precipitation of calcium carbonate because you are pushing alkalinity and calcium much too high to be stable.
I'm also not sure what you mean by usable carbon, but bacteria are not consuming the carbon that is part of any ordinary plastic container.