salt mix not dissolving completely

[gene71495]

I mixed one cup Oceanic salt mix to 2 gallon RO water. Placed a heater and air stone in and left six for two days. After the firts day I noticed some undissolved salt on the bottom of the bucket so I vigorously mixed. After the second day some undissolved salt remained. What am I doing wrong?

[jasonrp104]

What is the specific gravity? I'm guessing it's too much salt in too little water. I know Instant Ocean only needs a little over 1/2 cup per gallon to hit 1.023 at 78 degrees

[rush07]

There is either too much salt or not enough water movement to mix it completely. Also, if the water is cold it can cause this problem. Do you have a power head and heater you can use when mixing the salt?

[Ranchhand02]

Heat the water and add more water

[brianx45]

I would add a powerhead to help with the circulation.

[Randy Holmes-Farley]

It is typical for there to be some calcium carbonate accumulated on the bottom of salt mixing reservoirs. I show that here:

What is that Precipitate in My Reef Aquarium?
http://reefkeeping.com/issues/2005-07/rhf/index.htm

from it:

Figure 1. The residue on the bottom of the plastic trash can that I use to mix Instant Ocean. I rarely clean it out. The solid is most likely calcium carbonate.

http://www.reefkeeping.com/issues/2005-07/rhf/images/Figure_1.jpg

[fishoutawater]

I use a powerhead with a venturi to add some air and have never noticed any leftovers in my mixing bucket.

[NirvanaFan]

If the bucket is rinsed out between uses, then it could be a number of this. You should be able to dissolve a lot more than 1 cup of salt in 2 gallons of water.

If you just have an air stone in it, there probably isn't enough movement. Add a powerhead, or mix it by hand with a length of pvc pipe.

A higher temperature makes things dissolve more, and quicker. Try raising the temp with an aquarium heater if you have a spare.

Also, you added the salt to the water right? Adding water to salt could cause it to not dissolve and form a rock hard piece of salt.

[seapug]

As randy said, it's probably not salt. It's most likely Calcium carbonate that has precipitated. No amount of stirring or aeration will get rid of it, but I've found adding salt VERY slowly to the water helps keep it from happening-- probably because the mix completely dissolves before it has a chance to settle on bottom of the barrel where the high ph of a "pile" of mix can occur and cause the precip.

Bottom line is it's really nothing to be too concerned about. My mixing barrel looks exactly like the photo above.