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Do Goldfish Need Chemicals or Additives in Their Tanks? Facts & Safety Guide

Lindsey Stanton Profile Picture

By Lindsey Stanton

hand holding PH test

Goldfish were my first experience with aquariums. Fancy goldfish, no less. I went to the pet store, got what I “needed,” according to the aquarium staff, and off I went. I ran the tank for a few weeks, just like they tell you to. Needless to say, I did everything incorrectly the first time around.

What confused me the most were the chemicals. The pet shop recommends some (which, of course, you buy automatically), and a starter kit that comes with other chemicals you have no knowledge of. Can you use them together? Do you really need them? How often and how much do you put in? Many of these products don’t have the answers to most of these questions, and they are expensive products! So, I’d like to let beginners know what’s necessary and what isn’t.

What Chemicals You Don’t Need

Bacteria “starters” are usually recommended by stores. You can add all you want, but without fish in the tank, your aquarium cycle will not begin. I don’t claim to know what is actually in these products, but I know that they don’t work. I’ve switched tanks at least three times, and they did not speed up anything about making my tank fish-safe. In addition, when they tell you to run the tank, it is to check for equipment defects. It has nothing to do with the aquarium cycle itself.

With regard to pH products, don’t buy them. I repeat, don’t buy them. Unless you live in a place where the tap water is absolutely on one end or the other of the pH scale, you will only wind up on an endless hamster wheel to keep your pH properly balanced. Goldfish (and many other fish) can tolerate a fair range of pH values. It is sudden changes in pH that will harm your fish. You put yourself at risk for just that when you use these products.

If you need help getting the water quality in your aquarium just right for your goldfish family, or just want to learn more on the subject (and more!), we recommend that you check out our best-selling book, The Truth About Goldfish.

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It covers everything from water conditioners to nitrates/nitrites to tank maintenance and full access to our essential fishkeeping medicine cabinet!

Ammonia reducers and nitrate reducers are also to be avoided. There are products which claim that you can go 6 months without a water change. That is ridiculous. I don’t care what type of fish you keep, there is no cure for nitrates other than water changes. Repeat that three times in your mind, and your fish will thank you.

As for ammonia, when your tank has completed the aquarium cycle, it should read ZERO ammonia from there on out. Any ammonia at all is a sign that you are not cycled, and you should certainly not need it for maintenance.

checking ph levels
Image Credit: finchfocus, Shutterstock

So, Which Chemicals Should I Get?

What you do need is fairly simple. Get a good water conditioner (dechlorinator). There are many opinions as to which is the best. Ignore them and just be sure to use it every time you change the water, which should be at least weekly if your tank is properly stocked.

Buy aquarium salt. My store didn’t even mention this, but there are many, many illnesses and stressors that can be reduced if not cured by aquarium salt. The details are all there on a good goldfish site. I don’t use it all the time, but some people recommend doing so.

Finally (and this is sort of optional), get an ick treatment medication. You can try salt, but ick kills fish quickly and is so common that it may be in your best interest to already have it when you get your goldies home.

I have a box full of products, now probably expired, which I never even needed. Get these products, ignore the rest, and you won’t empty your pockets (or your aquarium livestock).

Featured Image Credit: Dmitri Ma, Shutterstock

Lindsey Stanton Profile Picture

Authored by

Lindsey discovered her passion for fish keeping after a junior high school field trip to the Shedd Aquarium in Chicago. Prior to becoming Editor-in-Chief of It's a Fish Thing, Lindsey studied marine biology at the University of California-Santa Cruz. She loves goldfish, tetras, and mystery snails, and recently began experimenting with a saltwater aquarium.

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