Goldfish are very low maintenance pets and are almost like decorations for your house… said no goldfish keeper ever. A big misconception about goldfish is that they are very low-maintenance pets, which is not exactly true. There are things you can do to make goldfish tanks lower maintenance, but even then, they will always need your daily attention. In this article, I will go over how to start a fancy goldfish tank and all the maintenance needed to keep goldfish alive and healthy.
Before you go out and buy goldfish, you will have to buy all the necessary products, set up your tank system, and prepare the tank and filters to handle the waste produced by your goldfish once you add them to your tank.
Necessary Items you need to buy:
The first thing you should do before buying some goldfish is buying their tank. This is an extremely important decision so I recommend you read my article linked here about choosing the appropriate tank size. In short, your tank should not be smaller than 25 gallons, but my recommendation is 40 gallons or more. However, if you can purchase or fit a larger tank, always buy the biggest tank possible no matter how many goldfish you plan to keep. A larger tank means doing less maintenance and fewer water changes and usually results in healthier goldfish for the average goldfish keeper. Also, be sure your tank is not taller than 2 feet because fancy goldfish do not do well in deep water conditions. All this is explained in detail in my article so again, I recommend reading it.
After you buy your tank, you should buy every product I have listed under “Things you need” linked here on my list of necessary and recommended goldfish products. It’s perfectly okay if you don’t buy these exact products, but you will at least need something similar for every necessary item listed. I also recommend buying the items listed under “additional things I recommend”, but they are not needed if you are on a budget.
Setting up the tank:
After you buy all the necessary or recommended products, it’s time to set up the tank. If you choose to buy a ground substrate, make sure to thoroughly wash and rinse any substrate in water before adding it to the tank, they usually carry a lot of dust. It’s best to add in the washed substrate before adding water in the tank, because adding the substrate to a full tank may result in the water becoming very dirty. It’s not that big of a problem but it is not ideal.
You then want to fill the tank up with water and add water conditioner to detoxify the harmful chemicals that come from tap water. You will need to use this water conditioner when first filling the tank, and every time you do a partial water change.
You then want to set up the filters on the tank. If you bought the sponge filters as I recommend in my article, this will be very easy. All you have to do is connect the air hose line that comes with the air pump to the air pump outlet and connect the other end of the hose to the top of the sponge filter where you will see a little extruded hole that the hose line fits perfectly over. Place the connected sponge filters in your tank, plug the air pump in, and now your filters are up and running.
The next thing to do is add a water heater, which I highly recommend for fancy goldfish. I recommend a temperature range of 72F-78F, but also consider reading my article about tank temperature linked here to get a better understanding of the effects of higher temperatures on a goldfish tank. Though adding a heater is not considered “necessary” by many hobbyists, I find it necessary to keep fancy goldfish healthy over the long term.
Tank decorations are completely optional. I recommend against most fake decor because it can be hazardous for the fish. This is because they can run into them and hurt their skin and scales. Fancy goldfish are extremely clumsy and delicate, and for this reason, it’s very important to keep their tank decorations strictly smooth and soft. Fancy goldfish are heavily domesticated animals and would not thrive in “natural” environments. You may feel like your tank does not feel “natural” enough, but remember that fancy goldfish are not technically “natural” animals. Plants are also completely optional. Though they are generally safe, it’s likely your goldfish will end up uprooting them and eating them over the long run. Many people have success with plants, but again, it’s completely your choice. The best stimulation you can provide for a goldfish is a fellow goldfish in their tank, and also maybe some sand for them to sift through all day would be nice too.
Cycling Your Tank:
After setting up your tank, you must make sure you have your tank cycled. I am not going to go into the specifics of tank cycling in this article however, I highly recommend you research it because it is crucial that your tank is cycled before adding goldfish. If your tank is not properly cycled before adding goldfish, they will likely die, please thoroughly research tank cycling. In short, tank cycling is establishing a beneficial bacteria colony in your filters. This beneficial bacteria is responsible for converting the ammonia your fish produce as waste and detoxifying it into a much less harmful compound called nitrate. During this tank cycling process is where I recommend using bottled bacteria to speed up the process and establish a strong bacteria colony, as well as using the water testing kit to ensure ammonia is being converted quickly into nitrate. In short, you will have the throw crushed up fish food into the tank to rot and produce ammonia and allow time for the bacteria colony to settle and establish in the filters so they can handle the ammonia production from the fish once you add them. You will know your tank is filtered once your water testing kit reads zero ammonia, zero nitrites, and an elevated nitrate level. It’s a complicated process, but it’s necessary.
So after your tank is cycled, you will then be ready to add your goldfish! I recommend buying fancy goldfish from Goldfish Island. Full disclosure: I am an affiliate of Goldfish Island, but that does not change the fact that I absolutely stand by them and honestly recommend them to anyone looking to buy good quality fancy goldfish. Many of the fish I own myself are from Goldfish Island. Be sure to float the bags they arrive in, in your tank for at least 25 minutes before releasing them into the water to allow the temperature of the bag water to slowly equalize with the temperature of the tank water. Remember, abrupt temperature changes are extremely harmful to goldfish.
If this is your first fish, then you don’t exactly have to worry about quarantining them but still beware of parasites. Parasites in goldfish are extremely common and this is why I recommend quarantining them in their own tank before exposing them to any of your other goldfish if you have any. I recommend running goldfish through anti-parasitic medications when first buying them, however, this is not always necessary. Some of my favorite medications or treatments to use during a 4-5 week “quarantine” period would be praziquantel powder, metronidazole, and good old aquarium salt. You can use all of these at once to help rid the goldfish of any potential parasites they are carrying. You can dose aquarium salt into the tank water for the entirety of the quarantine period, and dose the other medications as prescribed on their packages. I also recommend reading my article linked here about using salts with goldfish.
If you buy from Goldfish Island, you can use my discount code: LUKE
Goldfish Island link: https://www.goldfishisland.com/?ref=Luke
What kind of maintenance will you have to do every day? In all honesty, it’s not that much. The only daily things you have to do is make sure that they are getting enough light and getting properly fed.
How much should you feed your goldfish? In my opinion, the average goldfish keeper should feed their goldfish 2-4 times a day. Each feeding should be enough food that the feeding lasts at least 30 seconds, but not longer than 2 minutes. If you throw some food in there and it is all gone in 15 seconds, maybe you should add more, but if you put food in there and 5 minutes go by and it is still not finished yet, you have overfed them. It is better for the fish to eat many tiny feedings a day, rather than 1 or 2 large feedings, so if you can, spread the feedings throughout the day.
What should you feed your goldfish? There are many different feeds on the market such as flakes, pellets, gel foods, and many others. I recommend using sinking pellets because they are easiest to feed or prepare, typically do not cause buoyancy issues if fed in moderation, are relatively cheap, and do not make a mess in the tank. I recommend using Mizuho Feed as your base pellet feed because their ingredients are high quality, the protein content is pretty high, and my goldfish love it! Linked here is where you can buy their pellets!
What else should you feed to your goldfish? In addition to feeding pellets, I highly recommend adding some diversity to their diet. You should routinely feed some veggies including boiled broccoli, boiled and de-shelled peas, lightly boiled or softened spinach, lightly boiled or softened romaine lettuce, and many others! In the wild, goldfish routinely eat a lot of vegetation and greens, so it’s good to give them a diet plentiful in greens. Something to keep in mind when feeding veggies is that it’s okay to have big chunks of veggies stay in the tank for an extended time like a semi long-term snack, instead of only giving enough to eat in 30 seconds or so. You can also occasionally feed soft fruits like bananas or strawberries, but do this in moderation. Another option is feeding them algae that grows in the tank or pond, they love eating this. You also want to occasionally feed them live or frozen foods. I choose to always feed frozen foods over live foods because with live foods, there is a risk of them carrying a parasite and infecting your fish, however many hobbyists do this all the time with no problems. Two great frozen fish foods I use and recommend are frozen blood worms and frozen brine shrimp. You can buy these at most local and chain pet stores.
The ideal way to add diversity to a goldfish’s diet is by making 1 of the 2-4 daily feedings a “special” feeding. So if you choose to feed your fish 3 times a day, make 1 of those 3 feedings a veggie (broccoli spinach, peas..) or make that feeding a frozen food (Blood worms, brine shrimp). By having 1 “special” feeding a day, your goldfish will have more than enough diversity in their diet. I recommend feeding veggies, fruit, or algae much more often than feeding bloodworms or brine shrimp because their pellets already contain so much animal protein that the biggest need for diversity is from plants or algae. So I would only feed frozen foods up to once or twice a week, and the rest of the time, have the special feeding be a veggie or greens. Though it can be hard to give your goldfish a special feeding every day, and many days I am not able to, it is ideal for the fish. If you can do it this often, then do so. However, it’s not a big deal at all if you don’t, just make sure you spice their diet up at least weekly.
This section is pretty simple, make sure your goldfish gets at least 6-8 hours of moderate light per day, and also make sure they do not get more than 16-18 hours of light per day. If they are in a room with a big window, the window might be enough, if they are in your dark basement, then they will need some lights. Linked here are some of the LED lights I use. You can adjust the intensity and spectrum of the slight and also set timers to ensure your goldfish are getting enough time in the light. Just make sure they spend a decent part of the day in the light and a decent part of the day in the dark.
Weekly Maintenance will likely include doing a partial water change, possibly sucking out any debris or sludge in the substrate, possibly testing your water parameters with a water testing kit, and optionally cleaning off algae that grows on the glass.
Water Parameter Testing:
When first starting a goldfish tank, you may want to test the water daily. This is because you want to ensure that the filter is converting ammonia to nitrate properly. Once your tank is well established, this would be a few weeks or so after adding your fish, you then have to choose how often you test your water parameters. Some people recommend testing the water weekly, other folks recommend testing every other week, and I’ve even heard of some that test maybe once a month. In my opinion, the more frequently you test the water, the greater the chance you catch something that might go wrong in the system. I normally choose to test the water in my tanks every other week, with some tanks getting tests more often and other tanks getting tests less often, depending on how constant and unchanged the system is.
Ammonia and Nitrite
If you bought the water testing kit as described in my list of necessary items, then testing the water should not be that hard of a task. When testing for ammonia, the target for maintaining healthy water parameters is 0 PPM. When testing for nitrite, the target for maintaining healthy water parameters is also 0 PPM. If there is any ammonia or nitrite in the water, you either don’t have enough filtration in your tank, your bacteria colony is not well established in your filters and the tank is not properly cycled, you have too many fish, your tank is not big enough, or you are overfeeding. You could also decrease ammonia levels by adding fast-growing live plants. It’s important to understand that ammonia and nitrite are highly toxic. If you have any level of these compounds in the water, you must act quickly to save your fish. An emergency water additive you can use is SeaChem prime water conditioner, which detoxifies these compounds temporarily. You can dose this conditioner every day until these values read 0 PPM, to save your fish from dying. When trying to get the levels of ammonia or nitrite lower, consider adding more beneficial bacteria, adding more filters, giving away some of your fish, or getting a bigger tank.
When reading pH values for goldfish, the most important thing is that the pH level is relatively constant. Goldfish can tolerate a large pH range, but they cannot tolerate frequent swings between pH values, this will stress them out. If your pH value is between the range of 7.0 to 8.0 and is consistently at the same value, then your goldfish will generally be fine. Even if the pH value is a bit above or below this range, goldfish can adapt and will likely be fine. The ideal pH is around 7.6, but goldfish would much rather prefer the pH of what they are used to rather than this “ideal” pH. There are products on the market to raise, lower, or stabilize pH, but if you are doing proper water changes and have a well-filtered and maintained system, it’s best to not mess with the pH. Typically trying to adjust the pH can be more harmful than good, only if the pH is severely high or low, should you consider tampering with it.
The testing kit should also read the nitrate level. The rule of thumb with nitrates is you want to maintain the lowest amount of nitrate possible. I would recommend keeping the nitrate level at or below 25 PPM, however, if it creeps up higher than this, it’s not too big of a deal if it’s not above this level too long. If the nitrate level climbs above 50 PPM, then you’re starting to stress your goldfish out and you should lower it as soon as possible. The most common way to lower nitrate levels is by doing water changes. Water changes are the most effective and simple way to remove nitrates from a system. Generally, tap water has a nitrate level of 0-5 PPM (for some select locations it might be much higher), and replacing your tank water with tap water, simply drops the concentration of nitrates. The more water you change out, the lower the nitrate level will drop, the healthier your fish will be. You can also lower the nitrate level by adding fast-growing plants or by using a filter media that harbors anaerobic bacteria that removes nitrogen from the water and turns it into nitrogen gas. These methods generally are less effective at lowering nitrate levels than water changes however, when implemented correctly, they can help extend the time between water changes. However, no matter what you do you will still need to change out some water here and there.
You will likely need to do water changes roughly once a week, however, the need for water changes is highly dependent on your stocking level and tank size. Some overstocked tanks may require daily water changes, other tanks may only require one every two weeks. In general, the smaller your tank and the more goldfish you have, the more frequently you must change the water. It’s also important to keep in mind that larger goldfish produce more waste than smaller goldfish. The exact frequency and volume of water changes you choose to do are ultimately ruled by your nitrate level. As long as your nitrate level is in a healthy range, (see section above) you are likely doing enough water changes.
I am a big proponent of doing large volume water changes because I believe it’s beneficial to remove as much waste and nitrate as possible from the system. I like to remove 65%-85% of the water from my tanks when I change the water. However, you must be careful in doing large volume water changes because some new fish may be sensitive to them. Start by doing smaller volume water changes like 25%-35%, then slowly work your way to doing larger and larger volume water changes and allow your fish to slowly get used to a lot of fresh water at once. You will find it much easier to maintain low levels of nitrates by doing large water changes.
Some things to keep in mind when changing the water is that you need to add new water to your tank that is nearly identical in temperature to the water already in the tank. Do not add “hot” water or “cold” water, add water that feels the exact same in temperature to the current tank water. Failure to replace water at the same or near the tank temperature may result in the death of the goldfish. It’s also extremely important to add a water conditioner or water dechlorinator right BEFORE adding tap water into your tank. So you should drain the tank to the level of water you wish to remove, then add the water conditioner, then start adding new water. Having the conditioner in the water right as the new water comes in will help to quickly detoxify the chlorine or chloramines in tap water which are toxic to both fish and the bacteria colony in your filters of the tank. Failure to add a water conditioner when changing the water will likely result in the death of the goldfish AND the death of the bacteria in the biological filter media. Making sure the water temperature is the same and making sure to add a water conditioner are the most important things to keep in mind when changing water.
There are many different methods to changing water, my favorite is using a python water changer, I have a video tutorial linked here on how to use it. In short, it allows you to remove and add water to the tank from the same hose. It’s also on my list of recommended products. However, you don’t need a python water changer. You can also use any old bucket and tube to siphon the water from the tank into the bucket and use that same bucket to retrieve fresh water for the tank. In short, any way in which you can remove water from the tank and bring back fresh water at the same temperature as the tank is a viable way of changing water. Just make sure that if you choose to use a powerful water pump to empty the tank, it’s not too strong that it would suck up a little small goldfish.
This next step is optional, but I do it after every water change and have found it to help keep my water much more clear and tank sludge to a minimum. I dose this powdered beneficial bacteria linked here that’s meant for ponds in my water at roughly a 2-3x higher concentration than recommended on the package. This beneficial bacteria is highly concentrated so even when using 2-3x more than recommended, you will still only be using a pinch. It does take multiple weeks of consistent use to take any effect, but it does help things look cleaner.
Cleaning the Substrate:
If you do not have sand or gravel this should not be an issue for you, but those that have substrates in their tanks will find that sludge does build up in it over time. You might want to buy a gravel vacuum or just use the head of the python water changer to sift around through the substrate and suck up any debris trapped in there. You may find that with sand, you do not tend to have much debris down under the substrate, but with gravel or larger rocks, a lot of poop and food can get stuck in the crevasses. You may not need to clean the substrate weekly, but the more often you do it the better.
Some folks also clean the substrate by mixing it all up with their hand and allowing the debris to get suspended into the water and removed by the filters. This is a viable method of cleaning your substrate, but it clouds the water up and can make your filters a bit dirtier. It works, but if you can just use a gravel vacuum or python water changer, that is better.
Cleaning the Algae Off the Glass:
Over time, algae will grow on the glass and structures of the tank. You can choose to clean this surface algae off, or not. It typically does not harm or help the fish so it’s entirely your choice. However, if you have no substrate, you could try to grow an algae floor as almost a good snacking place for your goldfish. But typically, a little patch of green on the tank will not be significant enough for them to eat, so there is no benefit or harm to leaving it. If you don’t like the way it looks, you can scrub it off, but it’s entirely a personal preference. If you want to reduce the amount of algae that grows on the tank, consider having your lights on a lower setting, having your lights on for less time during the day, and keeping your nitrate level lower. Algae uses light for energy and nitrates for food. If you starve it of both, its growth rate will slow. Excessive growth of algae may be a sign of high nitrate levels, be sure you are doing enough water changes.
Monthly Maintenance will likely include cleaning out the filter and testing your water parameters if you do not already do it weekly.
Cleaning Out the Filter:
Depending on how heavily stocked your tank is and how many filters you have, you may need to clean your filters out every month, or much more often than that. Once you notice your filter sponges or filter paddings are looking very dirty and not as efficiently clearing up your water, it may be time to rinse them out. The most important thing to make sure of when cleaning your filter is that you remove dirt and sludge, while NOT killing the beneficial bacteria in the filter media.
The best way to do this is by using water from your tank to rinse out your filter media or sponges. You can pour tank water into a separate bucket and in that bucket, you can put your filter sponges or media and squeeze them to get the sludge out. Never use straight tap water to clean out filter paddings, sponges, or filter media. Tap water has chlorine or chloramines that could kill the beneficial bacteria in your filter media. Even when rinsing out your filter sponges in tank water, you don’t want to do too vigorously. If you are too thorough and vigorous in squeezing the dirt and sludge out of your filter sponges, you may even displace too much beneficial bacteria that is necessary for the filter sponges to work to turn ammonia into nitrate. I would try to remove a majority of the sludge from these filter paddings, but once you notice a fair amount of dirt released, it’s okay to stop and allow some sludge to stay embedded in the filters.
After rinsing out the filters, some of the beneficial bacteria will be somewhat removed along with the sludge, so it’s important to be careful the few days after a filter cleaning. Your filter’s capacity to convert ammonia to nitrate may be somewhat compromised directly after cleaning. If you can add bottled beneficial bacteria to the system directly after a filter cleaning that would be helpful, otherwise you can just decrease feedings and maybe dose some safe or prime, to temporarily detoxify any elevated values of ammonia or nitrite. You may not have any increase in ammonia at all after a filter cleaning, but it is something I have noticed occasionally in my tanks.
Testing the Water:
I would advise most goldfish keepers to test their water once a week or every other week, however, if you have been keeping your goldfish for many months or years, you might not need to test it so often. If you have had your goldfish tank or system for a very long time and you have not added more goldfish to it, have not made any feeding adjustments, and have not changed any factors in the system, then you may be able to get away with testing your water quality less often. If you are testing the water every week for a long time and the readings are healthy and unchanged every time you check it, then the risk associated with testing the water less often is very minuscule. Of course, the chance of you catching something wrong early goes up the more often you test the water, but after a certain time of consistent levels, it’s perfectly safe to start testing less often. Testing your system once a month if you have had your system for multiple years is very reasonable.
Some final words:
Along with maintaining a good diet and healthy water quality for your goldfish, it’s also important to regularly observe your fish and ensure they look healthy on the surface and behave in a normal and active manner. There are dozens of common diseases that goldfish can get, some due to poor conditions, and others for no clear reason. If something looks off in your goldfish, look up the symptoms and attempt to diagnose any problems sooner rather than later. I have multiple medications I like to use linked on my recommended products page of my website that can help fight various infections and problems.
I also want to stress the importance of doing your own additional research. Do not use this guide as your single source of information on how to care for your goldfish, but use it as a single reference along with multiple others. Never rely on a single source alone to gather your information for this hobby, even from me. There is so much disinformation out there along with a lot of good information, and the best way to differentiate the two is by finding multiple reliable sources that back the same or similar claims. Also, realize that there is typically more than one correct way to do something. Certain practices work for some keepers and don’t for others.
I allow everyone to access my articles and guides free of charge because I want everyone to learn how to keep goldfish successfully without having to pay extra fees in an already expensive hobby. However, if you feel that you have gained valuable insight from my guide and want to give support to this channel and site, consider joining my Patreon account linked here and becoming a member. The basic membership is $5 a month and includes bonus content, and the upper tier is $20 a month and in that tier, I also give unlimited chatting and phone calls to hobbyists that wish to have personalized help. And as a limited-time little bonus, I am naming some of my goldfish after my new members. Thank you all for reading and I hope this guide serves you well.
Also, special thanks to Sammy Piasecki (an Instagram follower) for giving me helpful grammar tips while writing this guide during an Instagram live video :)