Caking agents in table salt

[fishfever]

As I was pre-mixing up some salt with tank water for baths this morning I noticed the non-iodized table salt label said it used calcium silicate as an anti-caking agent. I wonder if this can be harmful to fish. I recall reading that certain anti-caking agents are harmful although I don't seem to recall anything about calcium silicate. I guess I should go out and buy a bag of rock salt which I don't think has any additives although it would take a lot longer to dissolve it. Anyone recall something bad about calcium silicate in table salt?

[Carl]

The anti-caking agents used in table salt (of which there are several, depending upon the manufacturer) are generally not a major danger to fish. However they can breed copious amounts of algae and cyanobacteria. For this reason I do not recommend their use in an aquarium except in a "pinch".
In baths/dips these caking agents are not an issue due to the short duration of a bath and non iodized table salt is perfectly safe for this use.

See this article:
Aquarium Answers; Salt in freshwater aquariums

Carl

[fishfever]

Thanks Carl, I'll continue using the table salt for the baths. But after reading your article (if I read it right) I'll probably need to cut back or stop using the Cichlid lake salt and switch to rock salt or another salt with no additives in the tank for the normal 1 tbsp/gallon concentration. I'm using Malawi buffer to get my acidic tap water to low 7's plus I always have Wonder shells in the tank and then the Cichlid lake salt on top of that so I could be pushing things on the extra minerals. Previously I was using just plain Aquarium salt but started the Cichlid lake salt when I ran out (although I'm using much less Cichlid lake salt per gallon as per the label).

[kagome]

You don't have to buy the expensive aquarium salt or use the not so convenient rock salt. You can buy water softener salt at any hardware/home improvement store or you can buy pool salt from the same stores, Walmart, or a pool supply store. Both water softener salt and pool salt are pure sodium with no caking agents and for about $5 you can get a bag of it that will last you practically forever. I have personally used the pool salt because that's what I already had lying around and Carl has suggested the water softener salt in the past.

[goldenpuon]

Sorry to get off topic but I have a question. I always heard never to use table salt for fish because it hurts them somehow. Is that true? Also, Carl, would you recommend using rock or water softener salt instead of aquarium salt?

Thanks.

Renee

[fishfever]

kagome, that's an excellent idea on the water softening salt. I think I have a few Home Depot gift cards I haven't used yet so it won't cost me anything. ;-)

[Carl]

Jun 25, 2009 12:08:53 GMT -5 goldenpuon said:

Sorry to get off topic but I have a question. I always heard never to use table salt for fish because it hurts them somehow. Is that true? Also, Carl, would you recommend using rock or water softener salt instead of aquarium salt?

Thanks.

Renee

I note this in the Aquarium Answers Salt article referenced in this article

As kagome noted water softener salt is perfectly fine as all it is is plain sodium chloride. I use Cichlid salt with wonder shells, but not usually with buffers unless test show it is needed since it has carbonates and other minerals similarly found in buffers.

As to table salt, the use of it in baths is generally perfectly fine, I just do not recommend its use other than in a pinch in the main aquarium. However as to hurting the fish, this is a myth. especially when you look at the chemistry of table salt as there is nothing toxic other than anti-caking agents (and trace iodine in some table salt)

Carl

[fishfever]

I went to the hardware stores and Walmart this weekend looking for water softener salt. The only thing I could find was huge bags of really large salt crystals (much larger than rock salt). One also appeared to have something in it to reduce iron, which I suppose might be helpful. I guess I could put the large crystals between two thick plastic sheets and hammer them into smaller crystals over a hard surface. Or is there a water softener salt available that is already in small crystals? I checked the pool section at Walmart but their salt had a high additive (something like 30-40%) of something other than sodium chloride.

[Carl]

Although I do not personally like the larger crystals, as long as it is pure Sodium Chloride, they will work, it will just take longer to disolve. I recommend pre-disolving in a cup /pitcher of water.

I would not use a salt with an iron reducing additive as this may or may not be desirable (small amounts of iron in the water is normal, some rivers have much higher amounts)

Carl

[fishfever]

The only problems I see with the larger crystals is time to dissolve and getting a reasonable measurement. As Carl states pre-dissolving them the day ahead of a water change solves the first problem. As for measurement, these crystals are as much as an inch long. Not very easy to measure in a tablespoon! What I did was weigh a random amount (turned out to be 11 oz) on a post office scale. Then I put them in a thick plastic bag and took a hammer to them over a hard concrete surface. I reweighed to make sure I hadn't lost crystals. Now they were the size of regular aquarium salt (probably a blender would have worked better). Using a tablespoon I measured about 15 tablespoons for the 11 oz weight. So for every tablespoon of salt I want to add I need to weigh 1.36 oz. of the water softener crystals on my post office scale.

[Carl]

Great idea, I really like the way you figure ways around problems!


Carl

[fishfever]

Thanks Carl, this is very economical at about $5 for a 40 lb bag, just a fraction of what I was paying for "aquarium" salt. Now I just weigh out the amount I need for a 5g water change and drop it in a clean jar filled with tap water at least a day ahead. I guess I could even drop in the amount of pH buffer needed for 5g as well. Then all I would need to add is some Prime when I actually do the water change.

[goldenpuon]

I quickly read your "Aquarium Answers Salt article" Carl and I was thinking of using water softener salt because it is cheaper than aquarium salt. But I'm not sure if it would have the the same minerals in aquarium salt my fish need if it would be a good choice . The aquarium salt I buy also says it contains extra electolytes so I would want to make sure the water softer salt has that.

I am also concerned because I would think the name "water softener salt" means it softens my water (reduces KH, GH, and PH). I have guppies and goldfish that need higher KH, GH, and PH values and I already struggle to keep these values up since my tapwater was a low PH. I wouldn't want to add a salt that would lower these values and cause my fish stress.

So, would water softener salt still be a good idea? Also, what brand of salt for example would I be looking for (which type has ingredients in it that is good for the type of fish I keep)? I don't want to add buy salt that has anything in it that could harm my fish or that has caking agents in it.

Thanks for your time.

Renee

[Carl]

This is a good question, however the use of pure sodium chloride water softener salt in an aquarium does not work the same way a water softener works, as a water softener simply uses salt as part of its process to replace calcium and magnesium ions in tap water with sodium ions (which is why water softened by this process is VERY bad for both FW & SW fish)

Most commercial aquarium salts are simply sodium chloride and have no added minerals. The minerals are present in products such as SeaChem Cichlid Salt which includes carbonates for buffering as well.
Wonder Shells can also add many of these important minerals (on a constant basis that keeps up with important mineral cations as well)

Here is a paste from an article that explains this well IMO:
The idea behind a water softener is simple. The calcium and magnesium ions in the water are replaced with sodium ions. Since sodium does not prec­ipitate out in pipes or react badly with soap, both of the problems of hard water are eliminated. To do the ion replacement, the water in the house runs through a bed of small plastic beads or through a chemical matrix called zeolite. The beads or zeolite are covered with sodium ions. As the water flows past the sodium ions, they swap places with the calcium and magnesium ions. Eventually, the beads or zeolite contain nothing but calcium and magnesium and no sodium, and at this point they stop softening the water. It is then time to regenerate the beads or zeolite.

Regeneration involves soaking the beads or zeolite in a stream of sodium ions. Salt is sodium chloride, so the water softener mixes up a very strong brine solution and flushes it through the zeolite or beads (this is why you load up a water softener with salt). The strong brine displaces all of the calcium and magnesium that has built up in the zeolite or beads and replaces it again with sodium. The remaining brine plus all of the calcium and magnesium is flushed out through a drain pipe. Regeneration can create a lot of salty water, by the way -- something like 25 gallons (95 liters).

Carl

[goldenpuon]

I'm sorry if I'm not following you on this. I read it but it is a bit hard for me to understand.

So you're saying water softener salt contains no minerals and aquarium salt is the same?

And you mean water softener salt doesn't soften the water like "pure" water softener so it is ok to use an an aquarium?

Last, what brand would of water softener salt would you recommend (if using it is a good idea)?

Sorry for all the questions. I just want to make sure I understand everything before I use water softener salt.

[Carl]

Most Aquariums salts do not have additional minerals, but no all (such as SeaChem's, but this is much more pricey as well)

The best I can say is to re-read the paste form the site about how home water softeners work, as this explains the process of softening water, which is a process that uses salt.
Think about it this way, when your body consumes sugars, they are converted into energy or stored, you do not simply become sweeter.
This is all a water softener does, is it uses salt for a process.

As to recommendations, as long as it is sodium chloride it is fine (I prefer a smaller "grain" size though, but fishfever gives some good ideas for use of larger salt "grains")

Carl

[goldenpuon]

Thanks for the post. I am understanding better now. Just a suggestion but you may want to add what we've discussed here to your Aquarium Answers Salt article.

As long as water softener salt does not soften water I am good (I want stable PH, GH, and KH values).
Water softener salt only softens water if water it is used in a water softener right, not if you just drop it in an ordinary aquarium?

That is the only thing I am not understanding so far. Part of it may be that I worded by questions poorly. Sorry about that.

[Carl]

Jul 3, 2009 13:52:44 GMT -5 goldenpuon said:

Thanks for the post. I am understanding better now. Just a suggestion but you may want to add what we've discussed here to your Aquarium Answers Salt article.

As long as water softener salt does not soften water I am good (I want stable PH, GH, and KH values).
Water softener salt only softens water if water it is used in a water softener right, not if you just drop it in an ordinary aquarium?

That is the only thing I am not understanding so far. Part of it may be that I worded by questions poorly. Sorry about that.

I will likely add this to the article at some time

Yes, water softener salt which is simply sodium chloride in most instances simply is used as a process to drive off calcium and magnesium ions. In an aquarium the small amount of sodium chloride does not allow for such a process.
This process is a reason why you cannot use zeolite in marine aquariums as it drives off ammonia, calcium and magnesium ions when mixed with high amount of salt in the water (brine).

Carl

[goldenpuon]

Thanks for clearing that up. I may use water softener salt in the future then. Thanks for your time.