How To Keep Your Goldfish Healthy And Growing

       Credit to photographer : Darren Chia


Attention : These are methods that I used for my goldfish and it turns out well. All parameters can be changed accordingly. For the feeding regime, I am using a regime that will maintain the vigor, stout form of goldfish and not just for "fun" keeping. 

 There has been a rumour going around about goldfish ever since I could remember. The rumour is that goldfish is not easily taken care of and  they easily get sick too. While this might be true (as compared to other pet fish), there are ways to prevent it.  If you have a system or a flow for your hobby, your fish will rarely get sick (unless due to inevitable circumstances such as no water change due to travelling etc. etc.).

Below are what you can do to keep your existing fish and new fish healthy and growing:



1. Quarantine New Goldfish

Quarantine : To separate your fish from the main tank/tub in another tank/tub to be treated with any kind of quarantine substance (JYP, Methylene blue, Salt). A simple set-up is enough such as a tank with an air pump. I suggest at least 30 litres of water per fish (3-4 inch fish).

Quarantine procedure for newly bought fish is extremely crucial whereby you can prevent an outbreak or spread of a disease introduced by the new fish. Goldfish (or any fish) from different farms/ breeders are raised in somewhat different environments. Some goldfish came from a cement/concrete pond...some came from a fibre glass tub..some came from a mud pond (a pond made by digging the ground). Different environments will have different microorganisms living in it. Usually the fish living in these environments have grown accustomed to the residential microbes and do not get sick easily.

When goldfish from different farms are mixed, the microorganism from one source can infect the fish from another source. The goldfish or the water that comes with it can carry these harmful microorganisms. Quarantine with salt or fish medicines can kill these microorganisms and prevent it from harming your existing fish. Or if the fish you just bought fall sick during quarantine, then you just saved your main tank from that particular disease.

I have tried many ways to quarantine the fish and these methods listed below are the ones I usually carry out. 

A. Quarantine using Salt

Salt can be used for certain microbes but its not effective for all. I usually use salt for local goldfish but it can be used for imported ones too.

# 0.5% salt treatment (5 grams of salt per litre of water) - used as treatment for goldfish during quarantine

B. Quarantine using Methylene Blue

Refer to the dosage on the packaging. There are many brands with different concentrations.


C. Quarantine using Japanese Yellow Powder

#1-2 grams Japanese Yellow Powder per 100 litres of water (adjust accordingly)

Note: Do not feed your fish during quarantine.



2. Quarantine Sick Goldfish

I practice quarantine for every fish that fell sick. Do not let them dwell in the same tank/tub with the other healthy fish. Separate them when you saw signs of sickness. Do not wait until the disease gets worse or becomes truly obvious.

Since there are many diseases and so many medications from an array of brands, I will just list down the easily obtained medications. Nowadays, each company labelled their products with the diseases that each medication can treat. Usually, they will mention what is the usage of the medication.

For goldfish, you can carry out:
~ a medicated bath : concentrated medication for a short period of time (minutes to hours)
~ longer period treatment (more commonly practiced): more diluted medication for a longer period of time.

A. Treatment using Salt (For gill flukes, body flukes and to introduce to new environment)

Bath: ~ 2% salt (20 grams of salt per litre) for 5 mins to 10 mins (adjust accordingly) - Usually used to kill of parasites such as gill flukes

Treatment: ~ 0.5% salt (5 grams of salt per litre) for 3 days up to 1 week - usually used as maintenance therapy after salt bath.

B. Treatment Using Methylene Blue (For white spot and fungus mainly)

Follow the instructions on the bottle.

C. Treatment Using Japanese Yellow Powder (For Aeromonas infections (Ulcers, dropsy, scale infections) and Columnaris infections (gill rot, fin rot, mouth rot)

Bath: ~5-10 grams in 100 litres of water (adjust according to volume of water) for 1- 4 hours

Treatment: ~1-2 grams in 100 litres of water (adjust according to volume of water) for  1 week. 

I do not suggest prolonged time in JYP solution. If needed to use for a prolonged time, do water change everyday for a week and top-up the JYP everytime.

Note: Do not feed your fish when its sick.

3. Water Change When Needed
Referring to normal situations (no sick fish),  feeding frequency affects the water change frequency. The volume of water/no. of fish per tank also affects the water change frequency.

• More food given = More water change
• Small volume of water = More water change
• High no. of fish = More water change

But this does not mean that you can starve your fish in order to maintain your water quality. Water change is necessary to maintain good water quality (crystal clear water with approx. neutral pH, Low ammonia, Low nitrate) but feeding is important to ensure good growth.


#Water change (for set-up with filter)
Water change mainly depends on your water volume. Large water volume for a small no. of fish requires less water change.

Ideal water change regime : 
Once (1 Time) every week (80% - 100%) 
OR 
Once every 2 weeks (for those with good filtration system)


#Water change (for set-up with no filter)
Ideal water change regime:
Once every 3 days (80% - 100%)
OR
Once everyday (20% - 30%)

Note: Adjust Water Change Frequency According to the Condition of the Water (Do WC when the water has a slightly murky appearance, has strong smell and you can see a lot of fish poop at the base of the tank/tub).



4. Feeding Adequately

"Do not overfeed your goldfish", a term that is being repeated almost everywhere. I have nothing against this phrase, it's good advice. However, I am against the practice of giving small amount of food just to avoid the water getting dirty.

Do you know that quite a number of fish in the market are stunted? They were not given adequate food and thus their growth rate slowed down or stopped entirely due to malnutrition.

We need to give our goldfish adequate food without worrying that too much food will make the water dirty. If you want your water to be crystal clear and still maintain your goldfish's growth, change the water more frequently (easy isn't it). This is for those who want their goldfish to grow healthily, if you wish to starve them just to avoid water change then do not keep goldfish as your pets. They defecate a lot, they eat a lot too.

Suggested Feeding Regime :

• For young goldfish (4 months - 1 year) = Feed  6 - 8 times daily

• For adult goldfish (2 years old - 3 years old) = Feed 4 - 6 times daily 

• For older fish (more than 3 years old) = Feed 2 -3 times daily 

Note: The figures above are merely suggestions, you can adjust accordingly. The key is small amount of food but frequent feeding. Add in a variety of food into the diet. Using food with wheat germ will aid digestion and can prevent swim bladder problems.



5. Stop petting/holding your fish regularly

Goldfish are not like your furry companions where you can pet them whenever you want to. Fish are aquatic life forms and the bacteria that exists on our skin/dry environment can cause harm to our fish. Petting them regularly might cause red sores to develop at the petting site (if done at a particular site frequently).

Nonetheless, you can still hold them during examination or when choosing new fish at the fish shop (ONLY do this if you are used to it and knows how to handle them).

 Just don't do it often after you get them as your pets. Holding them with a slightly tight grasp can damage their slime coat (which protects them from pathogens).



6. Observe your goldfish regularly

The key to avoid your goldfish from getting sick is to detect the early signs of sickness. If you have been observing them regularly, you will notice their behaviour and activity level. Healthy goldfish will always swim around the tank/tub. 

Look out for the following signs :

• Decrease in appetite
• Redness at the scales/fins/head
• Slightly torn fins
• Decrease in activeness
• Odd swimming style
• Difficulty in swimming
• Passive behaviour (swimming slowly or lying at the base of the tank quietly)
• Rubbing of their bodies onto objects or the wall of the tank
• Harassment from other goldfish
• Slightly open gill covers

Credit to :
Mr. Wee Yap, for the salt treatment dosage.
Rafflesgold Forum, for the Japanese Yellow Powder dosage.