Friday, April 13, 2012

Feeding your Goldfish

Occasionally, feeding of pond goldfish becomes a topic of extreme concern to the keepers of ponds.  Do not feed goldfish. This does not apply to koi. If you have koi, you have an outdoor aquarium and must deal with it accordingly. But not goldfish.

Here's why:

If you have a balanced pond, with underwater vegetation, your fish will be happy without unnecessary and artificial food introduced into the pond. 

If you feed them, they will grow bigger than the pond can handle, they will eat all the vegetation, so you will feed them more and more...and soon the bioload will be too big for the pond and all the fish will die.

If you have sufficient filtration, you can feed fish, but not without it. And overfeeding leads to foul and green water.

You must have enough submerged vegetation for the goldfish to eat and the submerged vegetation grows faster than the fish can eat it. 

Do not introduce more fish to your pond than 1 linear foot of fish per 25 square feet of pond surface.  

If you feed fish, they will be easily attacked by predators because they do not know the difference between you and a raccoon or a heron, so will come to the surface thinking they are going to get dinner and end up being dinner.

If you have grandchildren and they MUST feed the fish when they visit, make some chopped, cooked carrots and feed them sparingly, perhaps once weekly, no more.

And for all the science behind a balanced pond and to make your eyes glaze over:

Plants and fish benefit each other in two ways. First, fish and plants contribute to the successful functioning of the nitrogen cycle. As the waste products excreted by fish are released into the water, they are converted to ammonia and then to nitrites and nitrates by 
nitrifying bacteria. Nitrates are a food or fertilizer for plants and algae. As they are absorbed, plants and algae become a valuable food resource for fish, thus completing the nitrogen cycle. 

This ongoing biological cycle ensures healthy pond life. It is important to realize that if plants are not thriving, algae will take over and the water will become murky. 

A second important way fish and plants complement one other is through the process of photosynthesis. Fish require oxygen for their existence and they release carbon dioxide. Plants in turn require carbon dioxide for their successful existence and emit oxygen. 
During sunlight, plants will consume the carbon dioxide released by fish and in turn emit oxygen required by fish. 

A constantly functioning nitrogen cycle and photosynthesis are the key components to a successful and beautiful garden pond. 

Plants to use for best results:
The most beautiful type of pond plants are lilies. Water lettuce and water hyacinths are also excellent additions to the pond and submerged plants such as Hornwort, Vallisneria, Sagitarria, Cabomba and Anacharis are also excellent. 

The ideal pond fish are common or hardy goldfish. 

Now you can refocus your eyes.  Do not feed your goldfish. It's only common sense. 

In my book, I advocate not feeding fish, just as I do here.

You can buy my book here

It is consistently in the top ten best sellers in Landscaping.  Yippee.
It's on sale now for a buck.  Get it before the price goes back up.

And for pond info visit us at  You will find knowledgeable folks there who are glad to answer your questions.

Thank you for stopping by this morning.

And no, I don't know why the font keeps changing in this blog lately. Gremlins, maybe?


Levonne said...

Good research Jan!

Goldfish Gardner said...

This is very good to know, we were thinking about taking our new aquaponics set up out doors. I never would have thought not to feed the fish.
We feed our gold fish cucumbers about once a week and they seem to like those as well..I will have to try the carrots.

chrissie stevens said...

I've just put 4 goldfish in my small pond & wondered why the don't greedily attack the fish flakes I deposit every 2nd day. There's plenty of algae & some vegetation blown in. This blog has helped to simply identify my little fish are just not hungry with what nature has provided.

Jan Goldfield said...

You are right. Letting your fish eat what nature provides will keep them healthier and the pond clearer forever.