Ok, I'm going to keep on going. I'm canceling out carbon. Flip gave me a head up on filter media that will run me about $8 a year. My next question is about salt. The same guy that told me to use carbon told me to use non-iodized salt. 1tbs per 5 gallons. Reading around, this seems to be an old school practice also. 6-7 months ago I cut back to 1/2tbs with no ill effects. I'm thinking about going to 1/4 and eventually none. So, lets take a vote on this also. Do you use salt in your aquarium? If so why, if not why? Thanks-Nereus

i use it every water change but i do half of what it says on directions

I don't add salts to my aquariums unless treating illness/stress. Salts can be bad for plants in higher amounts so if you have any be careful when using salts.
Also remember when doing water changes that your starting volume is the same from the last time you dosed salts. When water evaporates the salts stay in your water. So if you replace water and salt make sure everything is the same or you could be raising your salinity over time.

Good point flip. I use RO/DI for evap. I'm not sure how the tap-water people do it. I put the same question out on another forum and got this response :

A fish is not just a fish, and if you don't know where it comes from and what it is adapted for, you can make terrible mistakes. Salt use is one of them.

Any rainforest fish, from the Amazon, West Africa or the jungles of Asia will suffer in salt. It is a skin irritant that causes the production of slime, and slime fights off infection on a fish. It also affects the density of water (it is a dissolved mineral) and that will mess up the kidneys of a fish evolved in mineral poor waters. You can kill some Corydoras catfish species, Apistogramma and blackwater tetras with salt.

Any coastal or hardwater fish will love salt in the water. Central American and East African fish love a little of it. So you have to know what is in your tank before you use it.

Water isn't just water, either. If you have mineral rich water, salt makes it mineral richer, and even harder. In soft water, salt adds one mineral to make the water harder. It'll kill the eggs of rainforest fish, and help the eggs of coastal fish. It kills the softwater parasite Oodinium, a great thing. It makes life tougher for cardinals, otocinclus and many other popular fish - a bad thing.

As a medication, it increases the buoyancy of a fish (at a cost to the kidneys) and it irritates the skin, provoking mucous production that makes parasites slide off, and that catches and blocks many disease causing organisms.

If you go into anything with a clear view of what you are doing, you can use it well. Just make sure you have researched your fish and your water first.
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So, that said, I'm going to wean my tank from salt. Thanks - Nereus

Sounds like salt is good for a med, and carbon is good for removing other meds. Other than those applications, they can stay on the back shelf. In my case.

(I get what you're saying Flip, about the starting point I misread it at first. I have the sharpie line on my tank )

Salt really depends on the species, as you've so succinctly pointed out, Nereus! I used to use a salt and mineral blend for my Tanganyikan Africans but would not use it for my blackwater SA fish, unless there was an ailment I was treating, which I would do in a hospital tank.

Back when I started in the hobby 30 years ago it was recommended to use ammonia absorbing media in your filter, because ammonia was a fish waste that we thought was constantly causing problems. There was no internet and I was going on pet store recommendations, since that's all I had. It wasn't until much later that I realized I was really interfering with the nitrogen cycle by removing ammonia.

Now we have info at our fingertips and I'm SO glad we have this local site where we can not only share info online, but we also have the opportunity to see in person each others' setups and learn new or innovative methods of doing things.

I have a Malawi tank, and have always used salt. For years, I used Seachem Cichlid Salt until I learned how much money I was pissing away. Then about three years ago, I started making my own salt/buffer recipe. Since that time, I have had much more active and colorful fish and seem to have fewer illnesses - basically never have any.

I do large water changes - very large - but that's not relevant, I guess. For every five gallons or so of replaced water, I use one teaspoon each of salt (I use Instant Ocean, but non-iodized salt will do fine), epsom salt, and baking soda. This keeps the GH and KH around 11-15, and buffers the water to right around a ph of 8...

Just my two cents... Some say it's a waste of money, but I'm convinced my fish are healthier. I have a 180g tank, so I buy large quantities at a time to save money...

Good luck!

True, true... ;-)