Saltwater

[ShepherdReefer]

I do have a question and was just wanting to know if this was right or if everyone experiences the same results.

When making up a new saltwater for a water change. If the new saltwater sets from more than 2 days, I can see small particles flowing in the water...looks like algae particles. I do know that other reefers use larger containers that sets for more than 2 days. I use two different brute containers, clean the container after each use, and still get the same results. Of course, this may not be a bad thing.

Before the last RO filter change, my meters were reading 000, use Red Sea salt/Coral Red Sea salt, have a heater in the container (78 degrees), and one small power head.

 

[Randy Holmes-Farley]

The particles are green?

What mix?

Some white calcium carbonate particles forming is very common.

I typically kept new salt water for a month or more. No algae because it was closed and dark.

 

[ShepherdReefer]

I use the Red Sea mix. I also keep my closed, not allowing light into the tank...well, only when opening the lid. The particles flowing looks brown.

 

[Randy Holmes-Farley]

I use the Red Sea mix. I also keep my closed, not allowing light into the tank...well, only when opening the lid. The particles flowing looks brown.

It is probably calcium carbonate. I'd ignore it.

What is that Precipitate in My Reef Aquarium? by Randy Holmes-Farley - Reefkeeping.com

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.

Solid Residues Remaining After Preparing Artificial Seawater
Most salt mixes leave behind a solid residue when dissolved, although the extent to which this occurs varies from brand to brand. I use Instant Ocean and rarely clean out the 44-gallon trashcan that I mix it in, so a significant residue builds up over time (Figure 1). In preparation for this article I removed some of this solid material, and found that it could be almost completely dissolved in hydrochloric acid with lots of bubbling. This demonstrates that these solids were probably calcium carbonate (CaCO3), perhaps also containing magnesium. Pure magnesium carbonate is undersaturated in seawater (which is detailed in later sections of this article) 1 and should dissolve in marine systems, so it isn't likely to be the precipitated material, although there may be significant magnesium in the calcium carbonate.

Based on the fact that the material exists as sheets that clearly did not arrive in the mix (as opposed to a fine powder which might have), I conclude that at least a significant fraction of this residue formed in the barrel. I cannot, however, rule out the possibility that some solid calcium or magnesium carbonate may have existed in the salt mix and was cemented together by additional precipitation of calcium carbonate during dissolution or storage.

When salt mixes are dissolved, there exist local regions where the salt concentration is very high. In those local regions, the calcium and alkalinity must also be very high. In fact, as seawater is concentrated by evaporation, there is a well-established series of minerals that precipitate as the salinity increases. In this series, calcium and magnesium carbonate are the first to precipitate, appearing at a specific gravity of about 1.140, which is about a 50% solution of salt in water.1 Such conditions may well exist on the bottom of a saltwater reservoir as the salt is dissolving.

With some mixes (but not the Instant Ocean that I use), the initial pH on dissolution may be very high (pH 8.5-9 +). As shown in detail later in this article, pH can play a dominant role in determining the rate of calcium carbonate precipitation, and such a high pH would make it more likely to precipitate.

It has been suggested by some aquarists that some salt mixes may contain anti-caking agents, such as clays. I do not know if this is true, but if it is, they may form part of the residue that is left behind after dissolution.

In order to minimize the formation of insoluble carbonate salts when mixing, the following suggestions may be helpful:

1. Add the salt to a full batch of water, rather than adding water slowly to a large batch of salt. The latter allows a greater time at much higher than natural seawater salinity, which may tend to precipitate calcium and magnesium salts.

2. Stir the mixture vigorously as it is being dissolved.

3. If using a mix with a high initial pH, aerate the mixture as well as stirring it. The aeration will reduce the pH.

 

[Dylan McKenzie Holloway]

if you read on the side of your bucket is says not to mix for longer than 4 hours. If you find your self needing to have your saltwater sit for a few days I might would think about switching up salt brands.

 

[Phil D.]

I use the Red Sea Pro and as stated above don't let it sit for more than 4 hours. I generally mix it up and wait a 1/2 hour and then do my change. If you let it sit, you get precipitate.

 

[ShepherdReefer]

Thanks guys.

 

[Randy Holmes-Farley]

if you read on the side of your bucket is says not to mix for longer than 4 hours. If you find your self needing to have your saltwater sit for a few days I might would think about switching up salt brands.

I do not think that advice from the manufacturer is particularly credible in the general case (their stated reasons are not accurate), but it is certainly true that any low pH or low alk mix will be less prone to precipitation, and heating a mix however you do it (pump or heater) may accelerate precipitation.

 

[code4]

I have had differing results over the years depending on the brand of salt I am using. I recently seen a YouTube video on you tube, saltwater mixing mistakes Top 15, by Bulk Reef Supply. Or something close to that. I found it interesting. And for me helpful. I know in the past I have used salts that made my water smell. Wish I would have kept notes. And others that mixed really clean and did not smell. Good luck in finding the right salt water mix for you. And Randy Holmes Farley is awesome! I would listen to him.

Shelley

 

[Sailingeric]

I had a bucket of Red Sea salt when started and it had small bits of stuff floating in it now and then when I mixed it up. I always figured it is a little of brine shrimp or something similar since it is naturally dried from the sea.

 

[Randy Holmes-Farley]

I had a bucket of Red Sea salt when started and it had small bits of stuff floating in it now and then when I mixed it up. I always figured it is a little of brine shrimp or something similar since it is naturally dried from the sea.

Just to clarify what some people confuse. No salt mix is just dried seawater. That doesn't work. Parts of it may be, but that's also true of table salt in many parts of the world.